@article { ISI:000228418700023, title = {Bioleaching of sand by the fungus fusarium oxysporum as a means of producing extracellular silica nanoparticles}, journal = {Advanced Materials}, volume = {17}, number = {7}, year = {2005}, month = {APR}, pages = {889+}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

A plant pathogenic fungus, Fusarium oxysporum, can be used as a biological model system for the extracellular bioleaching of hollow spherical silica nanoparticles (see Figure) from sand. The room-temperature synthesis of oxide nanomaterials using microorganisms starting from potential waste materials could lead to eco-friendly and economically viable methods for the large-scale synthesis of nanomaterials.

}, issn = {0935-9648}, doi = {10.1002/adma.200401176}, author = {Bansal, Vipul and Sanyal, A. and Rautaray, D. and Ahmad, Absar and Sastry, Murali} } @article { ISI:000227414900003, title = {Biological synthesis of stable vaterite crystals by the reaction of calcium ions with germinating chickpea seeds}, journal = {Crystal Growth \& Design}, volume = {5}, number = {2}, year = {2005}, month = {MAR}, pages = {399-402}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The total biological synthesis of CaCO3 crystals of the metastable vaterite polymorph at room temperature by simple protein-mediated reaction of aqueous Ca2+ ions with the CO2 generated during the root growth from germinating chickpea (Cicer arietinum) seeds is described. Highly stable vaterite crystals of spherical morphology are obtained, indicating that the proteins secreted from the roots during growth play a crucial role in stabilizing and directing the crystal growth.

}, issn = {1528-7483}, doi = {10.1021/cg0341858}, author = {Rautaray, D. and Sanyal, A. and Bharde, Atul A. and Ahmad, Absar and Sastry, M.} } @article { ISI:000232129900010, title = {Biosynthesis of gold and silver nanoparticles using emblica officinalis fruit extract, their phase transfer and transmetallation in an organic solution}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {5}, number = {10}, year = {2005}, month = {OCT}, pages = {1665-1671}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

The design, synthesis and characterization of biologically synthesized nanomaterials have become an area of significant interest. In this paper, we report the extracellular synthesis of gold and silver nanoparticles using Emblica Officinalis (amla, Indian Gooseberry) fruit extract as the reducing agent to synthesize Ag and Au nanoparticles, their subsequent phase transfer to an organic solution and the transmetallation reaction of hydrophobized silver nanoparticles with hydrophobized chloroaurate ions. On treating aqueous silver sulfate and chloroauric acid solutions with Emblica Officinalis fruit extract, rapid reduction of the silver and chloroaurate ions is observed leading to the formation of highly stable silver and gold nanoparticles in solution. Transmission Electron Microscopy analysis of the silver and gold nanoparticles indicated that they ranged in size from 10 to 20 nm and 15 to 25 nm respectively. Ag and Au nanoparticles thus synthesized were then phase transferred into an organic solution using a cationic surfactant octadecylamine. Transmetallation reaction between hydrophobized silver nanoparticles and hydrophobized chloroaurate ions in chloroform resulted in the formation of gold nanoparticles.

}, keywords = {Biosynthesis, Nanomaterials, Phase transfer, Transmetallation}, issn = {1533-4880}, doi = {10.1166/jnn.2005.184}, author = {Ankamwar, Balaprasad and Damle, C. and Ahmad, Absar and Sastry, M.} } @article { ISI:000233736400023, title = {Calcite growth in Cissus quadrangularis plant extract, a traditional Indian bone-healing aid}, journal = {Current Science}, volume = {89}, number = {10}, year = {2005}, month = {NOV}, pages = {1742-1745}, publisher = {CURRENT SCIENCE ASSN}, type = {Article}, address = {C V RAMAN AVENUE, PO BOX 8005, BANGALORE 560 080, INDIA}, abstract = {

Cissus quadrangularis, a plant that has been customarily used in the Indian subcontinent to hasten the process of healing in bone fractures, has been studied and exploited to synthesize calcite crystals. The plant extract serves as a rich source of calcium ions, which when reacted with CO2, leads to the formation of calcite crystals of highly irregular morphology indicating that bioorganic molecules present in the extract modulate the crystal morphology.

}, keywords = {bone fracture, calcite crystals, Cissus quadrangularis, traditional healing}, issn = {0011-3891}, author = {Sanyal, A. and Ahmad, Absar and Sastry, M.} } @article { ISI:000226804000015, title = {Controlling the optical properties of lemongrass extract synthesized gold nanotriangles and potential application in infrared-absorbing optical coatings}, journal = {Chemistry of Materials}, volume = {17}, number = {3}, year = {2005}, month = {FEB}, pages = {566-572}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Anisotropic metal nanoparticles have distinct optical behavior when compared with their spherical counterparts. In this report, we demonstrate a simple method involving the reduction of aqueous gold ions by the extract of the lemongrass plant leading to the formation of gold nanotriangles with interesting absorption in the near-infrared (NIR) region of the electromagnetic spectrum. We show that, by simple variation of the experimental conditions, it is possible to vary the size of the gold nanotriangles and, thus, to tune the absorbance of flat gold nanoparticles in the NIR region. The NIR absorption of the gold nanotriangles is expected to be of application in hyperthermia of cancer cells and in IR-absorbing optical coatings. We show that the lemongrass extract synthesized gold nanotriangles can be easily cast in the form of films on glass substrates and that these films are highly efficient in absorbing IR radiation for potential architectural applications.

}, issn = {0897-4756}, doi = {10.1021/cm048292g}, author = {Shankar, S. S. and Rai, A. and Ahmad, Absar and Sastry, M.} } @article { ISI:000229118100006, title = {Extracellular biosynthesis of bimetallic Au-Ag alloy nanoparticles}, journal = {Small}, volume = {1}, number = {5}, year = {2005}, month = {MAY}, pages = {517-520}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, keywords = {alloys, Biosynthesis, composites, enzymes, Nanoparticles}, issn = {1613-6810}, doi = {10.1002/smll.200400053}, author = {Senapati, S. and Ahmad, Absar and Khan, Mohammad Islam and Sastry, M. and Kumar, R.} } @article { ISI:000205747600006, title = {Extra-/intracellular biosynthesis of gold nanoparticles by an alkalotolerant fungus, trichothecium sp.}, journal = {Journal of Biomedical Nanotechnology}, volume = {1}, number = {1}, year = {2005}, month = {MAR}, pages = {47-53}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA}, abstract = {

The development of reliable, eco-friendly processes for the synthesis of nanoscale materials is an important aspect of nanotechnology. As part of our ongoing investigation into the use of fungi for nanoparticle synthesis, we report herein that depending on the reaction conditions of the fungus Trichothecium sp. with aqueous gold ions, gold nanoparticle synthesis can be controlled to occur either within the biomass or extracellularly. Moreover, we have found that reaction of gold ions with the Trichothecium sp. fungal biomass under stationary conditions results in the rapid extracellular formation of gold nanoparticles of spherical, rod-like and triangular morphology whereas reaction of the biomass under shaking conditions resulted in intracellular growth of the nanoparticles. It is believed that on changing the reaction conditions of the fungus with gold ions, the enzymes and proteins which are being released into the medium under stationary conditions do not get released under shaking conditions resulting in the formation of extracellular or intracellular gold nanoparticles respectively. The gold nanoparticles are not toxic to the cells and the cells continued to grow after the biosynthesis of the gold nanoparticles in both the cases.

}, keywords = {Biosynthesis, enzymes, Fungus, Gold, Morphology Control, Nanoparticles}, issn = {1550-7033}, doi = {10.1166/jbn.2005.012}, author = {Ahmad, Absar and Senapati, Satyajyoti and Khan, Mohammad Islam and Kumar, Rajiv and Sastry, Murali} } @article { ISI:000230286900008, title = {Fungus-mediated biosynthesis of silica and titania particles}, journal = {Journal of Materials Chemistry}, volume = {15}, number = {26}, year = {2005}, month = {MAY}, pages = {2583-2589}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

The synthesis of inorganic materials by biological systems is characterized by processes that occur at close to ambient temperatures, pressures and neutral pH. This is exemplified by biosilicification in marine organisms such as diatoms while laboratory-based synthesis of silica involves extreme temperature and pH conditions. We show here that silica and titania particles may be produced by challenging the fungus Fusarium oxysporum with aqueous anionic complexes SiF62- and TiF62- respectively. Extra-cellular protein-mediated hydrolysis of the anionic complexes results in the facile room temperature synthesis of crystalline titania particles while calcination at 300 degrees C is required for crystallization of silica.

}, issn = {0959-9428}, doi = {10.1039/b503008k}, author = {Bansal, Vipul and Rautaray, D. and Bharde, Atul A. and Ahire, Kedar C. and Sanyal, A. and Ahmad, Absar and Sastry, Murali} } @article { ISI:000230839600024, title = {Heavy-metal remediation by a fungus as a means of production of lead and cadmium carbonate crystals}, journal = {Langmuir}, volume = {21}, number = {16}, year = {2005}, month = {AUG}, pages = {7220-7224}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

We show here that reaction of the fungus, Fusarium oxysporum, with the aqueous heavy-metal ions Pb2+ and Cd2+ results in the one-step formation of the corresponding metal carbonates. The metal carbonates are formed by reaction of the heavy-metal ions with CO2 produced by the fungus during metabolism and thus provide a completely biological method for production of crystals of metal carbonates. The PbCO3 and CdCO3 crystals thus produced have interesting morphologies that are shown to arise because of interaction of the growing crystals with specific proteins secreted by the fungus during reaction. An additional advantage of this approach is that the reaction leads to detoxification of the aqueous solution and could have immense potential for bioremediation of heavy metals. Under conditions of this study, the metal ions are not toxic to the fungus, which readily grows after exposure to the metal ions.

}, issn = {0743-7463}, doi = {10.1021/la047132g}, author = {Sanyal, A. and Rautaray, D. and Bansal, Vipul and Ahmad, Absar and Sastry, Murali} } @article { ISI:000241519600041, title = {Fungus-mediated biotransformation of amorphous silica in rice husk to nanocrystalline silica}, journal = {Journal of American Chemical Society}, volume = {128}, number = {43}, year = {2006}, month = {NOV}, pages = {14059-14066}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Rice husk is a cheap agro-based waste material, which harbors a substantial amount of silica in the form of amorphous hydrated silica grains. However, there have been no attempts at harnessing the enormous amount of amorphous silica present in rice husk and its room-temperature biotransformation into crystalline silica nanoparticles. In this study, we address this issue and describe how naturally deposited amorphous biosilica in rice husk can be bioleached and simultaneously biotransformed into high value crystalline silica nanoparticles. We show here that the fungus Fusarium oxysporum rapidly biotransforms the naturally occurring amorphous plant biosilica into crystalline silica and leach out silica extracellularly at room temperature in the form of 2-6 nm quasi-spherical, highly crystalline silica nanoparticles capped by stabilizing proteins; that the nanoparticles are released into solution is an advantage of this process with significant application and commercial potential. Calcination of the silica nanoparticles leads to loss of occluded protein and to an apparently porous structure often of cubic morphology. The room-temperature synthesis of oxide nanomaterials using microorganisms starting from potential cheap agro-industrial waste materials is an exciting possibility and could lead to an energy-conserving and economically viable green approach toward the large-scale synthesis of oxide nanomaterials.

}, issn = {0002-7863}, doi = {10.1021/ja062113+}, author = {Bansal, Vipul and Ahmad, Absar and Sastry, Murali} } @article { ISI:000243157600086, title = {Physical manipulation of biological and chemical syntheses for nanoparticle shape and size control}, journal = {Applied Physics Letters}, volume = {89}, number = {26}, year = {2006}, month = {DEC}, pages = {Article No. 263105}, publisher = {AMER INST PHYSICS}, type = {Article}, address = {CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA}, abstract = {

A nanosynthesis scheme is demonstrated which renders excellent control of nanoparticle shape, size, and dispersity in a solution based synthesis process. The scheme, termed as percolative microcavity synthesis, involves the use of a granular medium with percolative microcavities which facilitate nearly similar grain size/shape dependent reaction zones limiting intrinsic growth inhomogeneities, enabling particle size/shape control. The viability of the process is demonstrated for the synthesis of gold nanoparticles by a plant extract based biological method as well as a chemical method. (c) 2006 American Institute of Physics.

}, issn = {0003-6951}, doi = {10.1063/1.2424272}, author = {Ogale, Satishchandra B. and Ahmad, Absar and Pasricha, R. and Dhas, Vivek V. and Syed, A.} } @article {18}, title = {Role of halide ions and temperature on the morphology of biologically synthesized gold nanotriangles}, journal = {Langmuir}, volume = {22}, number = {2}, year = {2006}, month = {JAN}, pages = {736-741}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

{In this paper, we demonstrate the effect of halide ions on the formation of biogenically prepared gold nanotriangles using the leaf extract of lemongrass (Cymbopogonflextiosus) plant. We have also studied the effect of halide ions on the morphology of biogenic nanotriangles. It has been shown that iodide ions have a greater propensity to transform flat gold nanotriangles into circular disklike structures as compared to other halide ions. The study also suggests that the presence of Cl- ions during the synthesis promotes the growth of nanotriangles, whereas the presence of I- ions distorts the nanotriangle morphology and induces the formation of aggregated spherical nanoparticles. The change in the morphology of gold nanotriangles has been explained in terms of the ability of the halide ions to stabilize or inhibit the formation of (I 11) faces to form [

}, keywords = {DME steam reforming, fuel cells, Hydrogen, Mixed oxides, supported Ga2O3, XPS}, issn = {1520-6106}, doi = {10.1021/la052055q}, author = {Rai, A. and Singh, A. and Ahmad, Absar and Sastry, M.} } @article { ISI:000240291900046, title = {Room-temperature biosynthesis of ferroelectric barium titanate nanoparticles}, journal = {Journal of the American Chemical Society}, volume = {128}, number = {36}, year = {2006}, month = {SEP}, pages = {Article No. JA063011M}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The syntheses of inorganic materials by biological systems is characterized by processes that occur close to ambient temperatures, pressures, and neutral pH, as is exemplified by biosilicification and biomineralization processes in nature. Conversely, laboratory-based syntheses of oxide materials often require extremes of temperature and pressure. We have shown here the extracellular, room-temperature biosynthesis of 4-5 nm ternary oxide nanoparticles such as barium titanate (BT) using a fungus-mediated approach. The tetragonality as well as a lowered Curie transition temperature in sub-10 nm particles was established, and the ferroelectricity in these particles was shown using Kelvin probe microscopy.

}, issn = {0002-7863}, doi = {10.1021/ja063011m}, author = {Bansal, Vipul and Poddar, Pankaj and Ahmad, Absar and Sastry, Murali} } @article { ISI:000249553200007, title = {Bio-milling technique for the size reduction of chemically synthesized BiMnO3 nanoplates}, journal = {Journal of Materials Chemistry}, volume = {17}, number = {37}, year = {2007}, month = {AUG}, pages = {3910-3914}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Wet- chemical techniques for the synthesis of complex oxide materials have advanced significantly; however, achieving finely dispersed nanoparticles with sizes less than 10 nm still remains challenging, especially for the perovskite family of compounds. On the other hand, a fungusmediated synthesis technique has recently shown potential to synthesize perovskites such as BaTiO3 with sizes as small as 5 nm. Here we report, for the first time, the use of fungal biomass, at room temperature, to break down chemically synthesized BiMnO3 nanoplates ( size similar to 150 - 200 nm) into very small particles (, 10 nm) while maintaining their crystalline structure and the phase purity. This novel technique that we have named as {\textquoteleft}{\textquoteleft} bio- milling{\textquoteright}{\textquoteright} holds immense potential for synergically utilizing both chemical and biological synthesis techniques to synthesize complex oxide nanoparticles with particle sizes less than 10 nm with the proper crystalline phase.

}, issn = {0959-9428}, doi = {10.1039/b706154d}, author = {Mazumder, Baishakhi and Uddin, Imran and Khan, Shadab and Ravi, Venkat and Selvraj, Kaliaperumal and Poddar, Pankaj and Ahmad, Absar} } @article { ISI:000252406100012, title = {CdS quantum dots: enzyme mediated in vitro synthesis, characterization and conjugation with plant lectins}, journal = {Journal of Biomedical Nanotechnology}, volume = {3}, number = {4}, year = {2007}, month = {DEC}, pages = {406-413}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA}, abstract = {

This paper presents the in vitro synthesis of CdS quantum dot nanoparticles using sulphite reductase and capping peptide in the presence of a co-factor alpha-NADPH, their characterization and conjugation with plant lectins, Jacalin and Chick pea lectin. Incubation of sulphite reductase with aqueous CdCl2, Na2SO3, and capping peptide in the presence of a-NADPH, which acts as a co-factor, resulted in the formation of CdS nanoparticles of dimensions 5-20 nm. These CdS nanoparticles were conjugated with plant lectins by EDAC mediated coupling. These observations are of significance, as it will help in the development of eco-friendly process for the formation of CdS nanoparticles and their application as fluorescent biolabels. Moreover the above studies will also help in designing a rational enzymatic strategy for the synthesis of nanomaterials of different chemical composition, shapes and sizes as well as their separation.

}, keywords = {bio-label, CdS quantum dots, conjugation, Enzyme, in vitro synthesis, Nanoparticles}, issn = {1550-7033}, doi = {10.1166/jbn.2007.045}, author = {Ansary, Abu Ayoobul and Kumar, S. Anil and Krishnasastry, M. V. and Abyaneh, Majid Kazemian and Kulkarni, Sulabha K. and Ahmad, Absar and Khan, Mohammad Islam} } @article { ISI:000244890900006, title = {Chemical, thermal and pH-induced equilibrium unfolding studies of fusarium solani lectin}, journal = {IUBMB Life}, volume = {59}, number = {1}, year = {2007}, month = {DEC}, pages = {34-43}, publisher = {WILEY-BLACKWELL}, type = {Article}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

The effect of urea, guanidine thiocyanate, temperature and pH was studied on the conformational stability of Fusarium solani lectin. Equilibrium unfolding with chemical denaturants showed that the lectin was least stable at pH 12 and maximally stable at pH 8.0 near its pI ( 8.7). Guanidine thiocyanate ( the concentration of denaturant at which the protein is half folded, D-1/2 = 0.49 M at pH 12) was found to be an eight times stronger denaturant than urea (D-1/2 = 3.88 M at pH 12). The unfolding curves obtained with fluorescence and CD measurements showed good agreement indicating a monophasic nature of unfolding and excluded the possibility of formation of any stable intermediate. The effect of pH on the lectin was found to be unusual as at acidic pH, the lectin showed a flexible tertiary structure with pronounced secondary structure, and retained its hemagglutinating activity. On the other hand, the lectin did not show any loss of conformation or activity upto 70 degrees C for 15 min. Moreover, thermal denaturation did not result in the aggregation or precipitation of the protein even at high temperatures. Thermal denaturation was also carried out in the presence of a low concentration of guanidine thiocyanate. Change in the enthalpy of transition (Delta H-m) varied linearly with transition temperature (T-m), which indicated that the heat capacity (Delta C-p =3.95 kJ (.) mol(-1) (.) K-1) of the lectin remained constant during the unfolding.

}, keywords = {Denaturation, Fusarium solani, guanidine, Lectin, thermal, Unfolding}, issn = {1521-6543}, doi = {10.1080/15216540601178075}, author = {Khan, Feroz and Ahmad, Absar and Khan, Mohammad Islam} } @article { ISI:000251714500004, title = {Complex carbohydrate specificity of lectin from fruiting body of ganoderma lucidum. a surface plasmon resonance study}, journal = {IUBMB Life}, volume = {59}, number = {12}, year = {2007}, month = {JAN}, pages = {758-764}, publisher = {JOHN WILEY \& SONS INC}, type = {Article}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

The thermodynamics and kinetics of binding of glycans and glycoproteins to Ganoderma lucidum lectin was studied using surface plasmon resonance. The lectin showed highest affinity for asialo triantennary N glycan (Ka = 3.52 x 10(5)) among the glycans tested. There was a several fold increase in affinity for glycoproteins compared to their corresponding glycans and coincident increase in contribution from enthalpy (Delta H), suggesting the involvement of hydrogen bonding in the interaction as well as involvement of protein-protein interactions. Increased affinity also showed increase in unfavorable negative binding entropy (Delta S) which was compensated with higher enthalpy. The glycoproteins showed faster association rates (k(1)) and the activation energy (E-1(double dagger)) in the association process was much lower for the glycoproteins than glycans, resulting in their faster associations. These observations elaborate the role of protein matrix in lectin-glycoconjugate interaction.

}, keywords = {ganoderma lucidum, glycans, Lectin, SPR}, issn = {1521-6543}, doi = {10.1080/15216540701663463}, author = {Thakur, Atul and Pal, Lakhan and Ahmad, Absar and Khan, Mohammad Islam} } @article { ISI:000250735600035, title = {Fungus-based synthesis of chemically difficult-to-synthesize multifunctional nanoparticles of CuAlO2}, journal = {Advanced Materials}, volume = {19}, number = {20}, year = {2007}, month = {NOV}, pages = {3295+}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

Fungal nanosynthesis of ternary CuAlO2 phase is achieved at 50 degrees C. This phase is chemically difficult to synthesize at low temperatures because of the incompatible oxidation chemistry of Cu and Al. The synthesized protein-capped water-dispersible nanoparticles show blue luminescence and radio-frequency absorption (see figure).

}, issn = {0935-9648}, doi = {10.1002/adma.200602605}, author = {Ahmad, Absar and Jagadale, Tushar C. and Dhas, Vivek V. and Khan, Shadab and Patil, Shankar and Pasricha, Renu and Ravi, Venkat and Ogale, Satishchandra B.} } @article { ISI:000244293000015, title = {Nitrate reductase-mediated synthesis of silver nanoparticles from AgNO3}, journal = {Biotechnology Letters}, volume = {29}, number = {3}, year = {2007}, month = {MAR}, pages = {439-445}, publisher = {SPRINGER}, type = {Article}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

Synthesis of silver nanoparticles using alpha-NADPH-dependent nitrate reductase and phytochelatin in vitro has been demonstrated for the first time. The silver ions were reduced in the presence of nitrate reductase, leading to the formation of a stable silver hydrosol 10-25 nm diam. and stabilized by the capping peptide. The nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-Vis absorption. These studies will help in designing a rational enzymatic strategy for the synthesis of nanomaterials of different chemical composition, shapes and sizes as well as their separation.

}, keywords = {Capping Peptide, enzymatic method, nitrate reductase, silver nanoparticles}, issn = {0141-5492}, doi = {10.1007/s10529-006-9256-7}, author = {Kumar, S. Anil and Abyaneh, Majid Kazemian and Gosavi, S. W. and Kulkarni, Sulabha K. and Pasricha, Renu and Ahmad, Absar and Khan, Mohammad Islam} } @article { ISI:000243572800014, title = {Purification and characterization of a lectin from endophytic fungus fusarium solani having complex sugar specificity}, journal = {Archives of Biochemistry and Biophysics }, volume = {457}, number = {2}, year = {2007}, month = {JAN}, pages = {243-251}, publisher = {ELSEVIER SCIENCE INC}, type = {Article}, address = {360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA}, abstract = {

A lectin from the mycelial extract of an endophytic strain of Fusarium solani was purified. Its hemagglutinating activity was inhibited by glycoproteins possessing N-linked as well as O-linked glycans. The thermodynamics and kinetics of binding of glycans and glycoproteins to F. solani lectin Was Studied using SUH ace plasmon resonance. The lectin showed high affinity for asialofetuin, asia-lofibrinogen, asialofibrinogen, and thyroglobulin: and comparatively low affinity for mucin, fetuin, fibrinogen, and holotransferrin. Glycoproteins showed glycans with significant contribution from enthalpy and positive entropy, suggesting several fold higher affinity than their corresponding g the involvement of non-polar protein-protein interaction. Moreover, the higher affinity of the glycoproteins was due to their faster association rates and low activation energy. (c) 2006 Elsevier Inc. All rights reserved.

}, keywords = {endophytic fungus, Fusarium solani, Lectin, Purification, SPR, Thermodynamic properties}, issn = {0003-9861}, doi = {10.1016/j.abb.2006.10.019}, author = {Khan, Feroz and Ahmad, Absar and Khan, Mohammad Islam} } @article { ISI:000245736400045, title = {Zirconia enrichment in zircon sand by selective fungus-mediated bioleaching of silica}, journal = {Langmuir}, volume = {23}, number = {9}, year = {2007}, month = {APR}, pages = {4993-4998}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

One of the important routes for the production of zirconia is by chemical treatment and removal of silica from zircon sand (ZrSixOy). We present here a completely green chemistry approach toward enrichment of zirconia in zircon sand; this is based on the reaction of the fungus Fusarium oxysporum with zircon sand by a process of selective extracellular bioleaching of silica nanoparticles. Since this reaction does not result in zirconia being simultaneously leached out from the sand, there is a consequent enrichment of the zirconia component in zircon sand. We believe that fungal enzymes specifically hydrolyze the silicates present in the sand to form silicic acid, which on condensation by certain other fungal enzymes results in room-temperature synthesis of silica nanoparticles. This fungus-mediated twofold approach might have vast commercial implications in low-cost, ecofriendly, room-temperature syntheses of technologically important oxide nanomaterials from potentially cheap naturally available raw materials like zircon sand.

}, issn = {0743-7463}, doi = {10.1021/la062535x}, author = {Bansal, Vipul and Syed, Asad and Bhargava, Suresh Kumar and Ahmad, Absar and Sastry, Murali} } @article { ISI:000257349100007, title = {Silicate nanoparticles by bioleaching of glass and modification of the glass surface}, journal = {Journal of Non-Crystalline Solids}, volume = {354}, number = {29}, year = {2008}, month = {JUL}, pages = {3433-3437}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Bioleaching is examined as a low temperature (50 degrees C) soft chemical approach to nanosynthesis and surface processing. We demonstrate that fungus based bioleaching of borosilicate glass enables synthesis of nearly monodispersed ultrafine (similar to 5 +/- 0.5 nm) silicate nanoparticles. Using various techniques such as X-ray diffraction, X-ray photoelectron spectroscopy and FTIR we compare the constitution and composition of the nanoparticles with that of the parent glass, and establish the basic similarities between the two. The bioleaching process is shown to enhance the non-bridging oxygen component and correspondingly influence the Si-O-Si network. The root mean square roughness of glass surface is seen to increase from 1.27 nm for bare glass to 2.52 nm for 15 h fungal processed case, this increase being equivalent to that for glass annealed at 500 degrees C. (c) 2008 Elsevier B.V. All rights reserved.

}, keywords = {Bioglass, Biomaterials, borosilicates, narroparticles}, issn = {0022-3093}, doi = {10.1016/j.jnoncrysol.2008.03.025}, author = {Kulkarni, Sneha and Syed, Asad and Singh, Sanjay and Gaikwad, Anil and Patil, Kashinath and Vijayamohanan, K. and Ahmad, Absar and Ogale, Satishchandra} } @article { ISI:000260776800015, title = {Structure and microbial synthesis of sub-10 nm Bi2O3 nanocrystals}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {8}, number = {8}, year = {2008}, month = {AUG}, pages = {3909-3913}, publisher = {AMER SCIENTIFIC PUBLISHERS}, address = {25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA}, abstract = {

After the advent of novel chemical and microbial techniques, providing control over grain size and shape of the nanomaterials, several binary-oxide materials have been explored in size less than 10 nm for their tunable physical properties. Bi2O3 nanoparticles have also redrawn attention due to their excellent properties, mostly as optoelectronic material. Here, we report the room-temperature biosynthesis of Bi2O3 nanoparticles in a size range of 5-8 nm by extra-cellularly challenging the plant pathogenic fungus-Fusarium oxysporum with the bismuth nitrate as precursor. The as-synthesized particle-surfaces are inherently functionalized by a robust layer of proteins which provides them very good stability in the aqueous medium. Structural investigation using selected area electron diffraction, high resolution transmission electron microscopy and powder XRD shows that particles are almost perfectly single crystalline and primarily crystallize in alpha-phase with monoclinic structure.

}, keywords = {Biosynthesis, fungi, High Refractive Index, High Resolution TEM, Nanoparticles}, issn = {1533-4880}, doi = {10.1166/jnn.2008.179}, author = {Uddin, Imran and Adyanthaya, Suguna D. and Syed, Asad and Selvaraj, K. and Ahmad, Absar and Poddar, Pankaj} } @article { ISI:000260807500005, title = {Taxol and 10-deacetylbaccatinIII induce distinct changes in the dynamics of caveolae}, journal = {FEBS Letters}, volume = {582}, number = {25-26}, year = {2008}, month = {OCT}, pages = {3595-3600}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Taxol treatment of HeLa cells resulted in a transient recruitment of Caveolin-1 to the cell surface followed by internalization. Interestingly, 20 min after 10-deacetylbaccatinIII (10-DAB) treatment, the caveolae displayed faster {\textquoteleft}kiss and run{\textquoteright} dynamics while BaccatinIII (BacIII) did not induce any change. Sustained phosphorylation of Caveolin-1 is observed upon treatment and between Taxol and 10-DAB, the former shows phosphorylated Raf-1, ERK1/2 and hyperphosphorylated Bcl-2 while the later showed much less magnitude of the same. BacIII treatment did not induce phosphorylation of Raf-1 or Bcl-2. It is possible that Taxol might act on multiple targets and the side chain may be crucial. (c) 2008 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.

}, keywords = {10-DeacetylbaccatinIII, BaccatinIII, Caveolae, Cytotoxicity, Kiss and run dynamic, Taxol, TIRFM}, issn = {0014-5793}, doi = {10.1016/j.febslet.2008.09.029}, author = {Ahmed, Neesar and Dasari, Sreekanth and Srivastava, Saumya S. and Sneh, Amita and Ahmad, Absar and Khan, Mohammad Islam and Krishnasastry, M. V.} } @article { ISI:000272302200009, title = {Production, purification, and characterization of taxol and 10-DABIII from a new endophytic fungus gliocladium sp isolated from the Indian yew tree, taxus baccata}, journal = {Journal of Microbiology and Biotechnology}, volume = {19}, number = {11}, year = {2009}, month = {NOV}, pages = {1342-1347}, publisher = {KOREAN SOC MICROBIOLOGY \& BIOTECHNOLOGY}, address = {KOREA SCI TECHNOL CENTER \#507, 635-4 YEOGSAM-DONG, KANGNAM-GU, SEOUL 135-703, SOUTH KOREA}, abstract = {

We have isolated endophytic fungi from the Indian yew tree, Taxus baccata, and then screened for taxol production. Out of the 40 fungal cultures screened, one fungus Gliocladium sp. was found to produce taxol and 10-DABIII (10-deacetyl baccatin III). These compounds were purified by TLC and HPLC and characterized using UV-spectroscopy, ESI-MS, MS/MS, and proton NMR. One liter of Gliocladium sp. culture yielded 10 mu g of taxol and 65 mu g of 10-DABIII. The purified taxol from the fungus showed cytotoxicity towards cancer lines HL-60 (leukemia), A431 (epidermal carcinoma), and MCF-7 (breast cancer).

}, keywords = {10 DAB III, Endophytic fungi, Gliocladium sp., Taxol, Taxus baccata}, issn = {1017-7825}, doi = {10.4014/jmb.0904.04041}, author = {Sreekanth, D. and Syed, A. and Sarkar, S. and Sarkar, Dhiman and Santhakumari, B. and Ahmad, Absar and Khan, Mohammad Islam} } @article { ISI:000275161600003, title = {Biotechnology of endophytic fungi: inorganic nanomaterials and drugs}, journal = {Medicinal Chemistry Research}, volume = {19}, number = {1}, year = {2010}, month = {FEB}, pages = {S3}, publisher = {BIRKHAUSER BOSTON INC}, address = {675 MASSACHUSETTS AVE, CAMBRIDGE, MA 02139 USA}, issn = {1054-2523}, author = {Ahmad, Absar} } @article { ISI:000274401600036, title = {Steady state and time resolved fluorescence quenching and chemical modification studies of a lectin from endophytic fungus fusarium solani}, journal = {Journal of Fluorescence}, volume = {20}, number = {1}, year = {2010}, month = {JAN}, pages = {305-313}, publisher = {SPRINGER/PLENUM PUBLISHERS}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

The solute quenching studies of a lectin from endophytic fungus Fusarium solani were carried out using different quenchers such as acrylamide, succinimide, potassium iodide and cesium chloride. The lectin showed emission maximum at 348 nm indicating relative exposure of tryptophan. The quenchable fraction of the fluorophore was 100\% with acrylamide, whereas it was only 50\% with succinimide. The ionic quenchers iodide and cesium showed opposite effects at different pH. In the case of cesium, raising the pH resulted in increased quenching and accessibility of typtophan residue, while the iodide showed just opposite effect. These studies showed that the single tryptophan residue of the lectin (per monomer) is relatively exposed, and might be in the vicinity of positively charged amino acid residues. Various amino acids of the F. solani lectin were modified using different reagents to obtain information about the hemagglutinating site. The chemical modification studies suggested tyrosine residues can be modified using N-acetylimidazole, which results in complete loss of hemagglutination activity of the lectin. Kinetics of chemical modification suggested involvement of only 2 tyrosine residues. Modification of arginine, cysteine, histidine, lysine, aspartate, glutamate and tryptophan did not result in loss of hemagglutinating activity of the lectin.

}, keywords = {Chemical modification, fluorescence, Fusarium, Lectin, Quenching, Time-resolved}, issn = {1053-0509}, doi = {10.1007/s10895-009-0556-x}, author = {Khan, Feroz and Ahmad, Absar and Khan, Mohammad Islam} } @article { ISI:000306045000005, title = {Extracellular biosynthesis of platinum nanoparticles using the fungus fusarium oxysporum}, journal = {Colloids and Surfaces B-Biointerfaces}, volume = {97}, year = {2012}, month = {SEP}, pages = {27-31}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Nanoscience is a blooming field and promises a better future. In order to fabricate nanoparticles in an eco-friendly and inexpensive manner, significant efforts are being made to replace the chemical and physical methods currently being used with the biological methods. Chemical methods are toxic while the physical ones are very expensive. Biological methods, apart from being cost-effective, also provide protein capped nanoparticles which are thus very stable, have good dispersity and do not flocculate, and may find use in various applications. The present work emphasizes on platinum nanoparticles synthesis protocol which occurs at ambient conditions. The fungus Fusarium oxysporum when incubated with hexachloroplatinic acid (H2PtCl6) in ambient conditions reduces the precursor and leads to the formation of stable extracellular platinum nanoparticles. The biosynthesis of platinum nanoparticles was monitored by UV-visible spectroscopy and these nanoparticles were completely characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The nanoparticles are in the size range of 5-30 nm and are stabilized by proteins present in the solution. The reduction process is believed to occur enzymatically, thus creating the possibility of a rational, fungal-based method for the synthesis of nanoparticles over a wide range of chemical compositions. (C) 2012 Elsevier B.V. All rights reserved.

}, keywords = {Biosynthesis, Fungus, Nanoparticles, platinum}, issn = {0927-7765}, doi = {10.1016/j.colsurfb.2012.03.026}, author = {Syed, Asad and Ahmad, Absar} } @article { ISI:000305767200035, title = {Intracellular synthesis of gold nanoparticles using alga tetraselmis kochinensis}, journal = {Materials Letters}, volume = {79}, year = {2012}, month = {JUL}, pages = {116-118}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The development of eco-friendly synthesis protocol for the synthesis of nanoscale materials of different compositions, shapes and sizes is an important area of research in the field of nanotechnology. In this paper, we report on the use of alga Tetraselmis kochinensis in the intracellular synthesis of gold nanoparticles of dimensions 5-35 nm. The particles are more concentrated upon the cell wall than on the cytoplasmic membrane, possibly due to reduction of the metal ions by enzymes present in the cell wall and cytoplasmic membrane. These intracellular nanoparticles may have applications in drug delivery, biomedical applications, catalysis, etc. (C) 2012 Elsevier B.V. All rights reserved.

}, keywords = {Algae, Biosynthesis, Nanoparticles, nanotechnology, Tetraselmis kochinensis}, issn = {0167-577X}, doi = {10.1016/j.matlet.2012.04.009}, author = {Senapati, Satyajyoti and Syed, Asad and Moeez, Sana and Kumar, Ashutosh and Ahmad, Absar} } @article { ISI:000312542600011, title = {Phytosynthesis of intracellular and extracellular gold nanoparticles by living peanut plant (Arachis hypogaea L.)}, journal = {Biotechnology and Applied Biochemistry}, volume = {59}, number = {6}, year = {2012}, month = {NOV}, pages = {471-478}, publisher = {WILEY-BLACKWELL}, type = {Article}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

Inorganic nanomaterials of different chemical compositions are conventionally synthesized under harsh environments such as extremes of temperature, pressure, and pH. Moreover, these methods are eco-unfriendly and cumbersome, yield bigger particles, and agglomerate because of not being capped by capping agents. In contrast, biological synthesis of inorganic nanomaterials occurs under ambient conditions, namely room temperature, atmospheric pressure, and physiological pH. These methods are reliable, eco-friendly, and cheap. In this paper, we report for the first time the extracellular and intracellular synthesis of gold nanoparticles (GNPs) using living peanut seedlings. The formed GNPs were highly stable in solution and inside the plant tissue. Transmission electron microscopy revealed that extracellular GNPs distributions were in the form of monodispersed nanoparticles. The nanoparticles ranged from 4 to 6 nm in size. The intercellular nanoparticles were of oval shape and size ranged from 5 to 50 nm. Both extracellular and intracellular nanoparticles were further characterized by standard techniques. The formed GNPs inside the plant tissue were estimated by inductively coupled plasma spectrometry. This opens up an exciting possibility of a plant-based nanoparticle synthesis strategy, wherein the nanoparticles may be entrapped in the biomass in the form of a film or produced in the solution, both of which have interesting applications.

}, keywords = {cells, extracellular, living plant, Peanut, root, TEM}, issn = {0885-4513}, doi = {10.1002/bab.1049}, author = {Raju, Dugyala and Mehta, Urmil J. and Ahmad, Absar} } @article { ISI:000323396800020, title = {Biological synthesis of silver nanoparticles using the fungus humicola sp and evaluation of their cytoxicity using normal and cancer cell lines}, journal = {Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy}, volume = {114}, year = {2013}, month = {OCT}, pages = {144-147}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Nanoscience is a new born science of the modern era and taps into the potential of particles at nanoscale. Bulk materials reduced to nanoscale dimensions thus obtain unique properties such as electronic, optical, magnetic and chemical. As far as synthesis of nanoparticles is concerned, biological synthesis has recently sparked a great interest as compared to other available chemical and physical methods on account of its eco-friendliness and cost-effectiveness. Here we report, for the first time, the biosynthesis of silver nanoparticles by the thermophilic fungus Humicola sp. The fungus when reacted with Ag+ ions reduces the precursor solution and leads to the formation of extracellular nanoparticles as monitored by ultra violet visible spectroscopy (UV-Vis). The morphology of nanoparticles is found to be spherical with good dispersity as revealed by transmission electron microscopy (TEM). Cell viability assays were carried out to assess the cytotoxicity of silver nanoparticles on NIH3T3 mouse embryonic fibroblast cell line and MDA-MB-231 human breast carcinoma cell line. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {Cell viability, Fungus, Humicola sp., Nanoparticles, Silver}, issn = {1386-1425}, doi = {10.1016/j.saa.2013.05.030}, author = {Syed, Asad and Saraswati, Supriya and Kundu, Gopal C. and Ahmad, Absar} } @article { ISI:000317939100003, title = {Biotransformation of vinblastine to vincristine by the endophytic fungus fusarium oxysporum isolated from catharanthus roseus}, journal = {Biocatalysis and Biotransformation}, volume = {31}, number = {2}, year = {2013}, month = {APR}, pages = {89-93}, publisher = {INFORMA HEALTHCARE}, address = {TELEPHONE HOUSE, 69-77 PAUL STREET, LONDON EC2A 4LQ, ENGLAND}, abstract = {

A fungal transformation method for the production of the less abundant but more valuable anticancer drug vincristine using the more abundant anticancer drug vinblastine by an endophytic fungus Fusarium oxysporum isolated from the plant Catharanthus roseus is described. Vinblastine dissolved in sterile water when incubated with the fungal mycelial mass was transformed into vincristine at room temperature. The biotransformation process was monitored by periodic sampling of aliquots that were extracted with ethyl acetate. The crude transformed compounds were analysed using TLC where the Rf value of the spot obtained on the 8th day was found to be similar to that of standard vincristine (Rf 0.74). Purification by HPLC using a C 18 symmetry column showed a peak with RT (34.9 min) similar to that of standard vincristine. Further characterization with the help of ESI-MS showed a peak at m/z 825 attributed to the (M + H)(+) ion. This indicated that the fungus Fusarium oxysporum had converted vinblastine to vincristine.

}, keywords = {Biotransformation, endophytes, fusarium oxysporum, Vinblastine, vincristine}, issn = {1024-2422}, doi = {10.3109/10242422.2013.776544}, author = {Kumar, Ashutosh and Ahmad, Absar} } @article { ISI:000317836000016, title = {Extra- and intracellular gold nanoparticles synthesis using live peanut callus cells}, journal = {Current Nanoscience}, volume = {9}, number = {1}, year = {2013}, month = {FEB}, pages = {107-112}, publisher = {BENTHAM SCIENCE PUBL LTD}, address = {EXECUTIVE STE Y-2, PO BOX 7917, SAIF ZONE, 1200 BR SHARJAH, U ARAB EMIRATES}, abstract = {

An important challenge of considerable topical significance in nanotechnology is the development of eco-friendly experimental processes for the synthesis of nanomaterials in large quantities with variable sizes, shapes and chemical compositions. Green synthesis routes for the production of inorganic metal nanoparticles using whole cell of microorganisms and plant extracts are gaining tremendous popularity as these are non-toxic, cheap and occur at ambient conditions. The present work emphasizes on gold nanoparticles synthesis protocol using live plant callus cells. Peanut callus cells when incubated with HAuCl4 solution in ambient conditions reduced the precursor and lead to formation of well dispersed, water soluble extracellular and intracellular gold nanoparticles within 24 hours. The biosynthesis of gold nanoparticles was monitored by UV-visible spectroscopy (UV-Vis) and further characterized by X-ray diffraction analysis (XRD), Energy Dispersive Spectroscopy (EDS) and Selected Area Electron Diffraction (SAED). The particle size distribution shows that the average particle size is 50 nm for extra-and 31 nm for intracellular gold nanoparticles. The nanoparticles may be stabilized by proteins secreted by callus cells. The reduction process is believed to occur enzymatically, thus creating the possibility of a rational, plant cell-based method for the synthesis of nanoparticles over a wide range of chemical compositions.

}, keywords = {Biosynthesis, callus, gold nanoparticles, live cells, Peanut, TEM}, issn = {1573-4137}, author = {Raju, D. and Mehta, Urmil J. and Ahmad, Absar} } @article { ISI:000317545600006, title = {Extracellular biosynthesis of CdTe quantum dots by the fungus fusarium oxysporum and their anti-bacterial activity}, journal = {Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy}, volume = {106}, year = {2013}, month = {APR}, pages = {41-47}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The growing demand for semiconductor [quantum dots (Q-dots)] nanoparticles has fuelled significant research in developing strategies for their synthesis and characterization. They are extensively investigated by the chemical route; on the other hand, use of microbial sources for biosynthesis witnessed the highly stable, water dispersible nanoparticles formation. Here we report, for the first time, an efficient fungal-mediated synthesis of highly fluorescent CdTe quantum dots at ambient conditions by the fungus Fusarium oxysporum when reacted with a mixture of CdCl2 and TeCl4. Characterization of these biosynthesized nanoparticles was carried out by different techniques such as Ultraviolet-visible (UV-Vis) spectroscopy, Photoluminescence (PL), X-ray Diffraction (XRD), X-ray Photoelectron spectroscopy (XPS), Transmission Electron Microscopy (TEM) and Fourier Transformed Infrared Spectroscopy (FTIR) analysis. CdTe nanoparticles shows antibacterial activity against Gram positive and Gram negative bacteria. The fungal based fabrication provides an economical, green chemistry approach for production of highly fluorescent CdTe quantum dots. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {antibacterial activity, Biosynthesis, CdTe, Fungus, Nanoparticles}, issn = {1386-1425}, doi = {10.1016/j.saa.2013.01.002}, author = {Syed, Asad and Ahmad, Absar} } @article { ISI:000324077700076, title = {Fungus mediated synthesis of biomedically important cerium oxide nanoparticles}, journal = {Materials Research Bulletin}, volume = {48}, number = {10}, year = {2013}, month = {OCT}, pages = {4134-4138}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Nanomaterials can be synthesized by chemical, physical and the more recently discovered biological routes. The biological routes are advantageous over the chemical and physical ones as unlike these, the biological synthesis protocols occur at ambient conditions, are cheap, non-toxic and eco-friendly. Although purely biological and bioinspired methods for the synthesis of nanomaterials are environmentally benign and energy conserving processes, their true potential has not been explored yet and attempts are being made to extend the formation of technologically important nanoparticles using microorganisms like fungi. Though there have been reports on the biosynthesis of oxide nanoparticles by our group in the past, no attempts have been made to employ fungi for the synthesis of nanoparticles of rare earth metals or lanthanides. Here we report for the first time, the bin-inspired synthesis of biomedically important cerium oxide (CeO2) nanoparticles using the thermophilic fungus Humicola sp. The fungus Humicola sp. when exposed to aqueous solutions of oxide precursor cerium (III) nitrate hexahydrate (CeN3O9 center dot 6H(2)O) results in the extracellular formation of CeO2 nanoparticles containing Ce (III) and Ce (IV) mixed oxidation states, confirmed by X-ray Photoemission Spectroscopy (XPS). The formed nanoparticles are naturally capped by proteins secreted by the fungus and thus do not agglomerate, are highly stable, water dispersible and are highly fluorescent as well. The biosynthesized nanoparticles were characterized by UV-vis spectroscopy, Photoluminescence spectroscopy (PL), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and X-ray Photoemission Spectroscopy (XPS). (c) 2013 Elsevier Ltd. All rights reserved.

}, keywords = {Electron microscopy, Nanostuctures, Optical properties, Oxides, X-ray diffraction}, issn = {0025-5408}, doi = {10.1016/j.materresbull.2013.06.038}, author = {Khan, Shadab Ali and Ahmad, Absar} } @article { ISI:000324494000004, title = {Isolation, purification and characterization of vinblastine and vincristine from endophytic fungus fusarium oxysporum isolated from catharanthus roseus}, journal = {Plos One}, volume = {8}, number = {9}, year = {2013}, month = {SEP}, pages = {UNSP e71805}, publisher = {PUBLIC LIBRARY SCIENCE}, address = {1160 BATTERY STREET, STE 100, SAN FRANCISCO, CA 94111 USA}, abstract = {

Endophytic fungi reside in a symbiotic fashion inside their host plants, mimic their chemistry and interestingly, produce the same natural products as their hosts and are thus being screened for the production of valuable compounds like taxol, camptothecin, podophyllotoxin, etc. Vinblastine and vincristine are excellent anti-cancer drugs but their current production using plants is non-abundant and expensive. In order to make these drugs readily available to the patients at affordable prices, we isolated the endophytic fungi from Catharanthus roseus plant and found a fungus AA-CRL-6 which produces vinblastine and vincristine in appreciable amounts. These drugs were purified by TLC and HPLC and characterized using UV-Vis spectroscopy, ESI-MS, MS/MS and H-1 NMR. One liter of culture filtrate yielded 76 mu g and 67 mu g of vinblastine and vincristine respectively. This endophytic fungal strain was identified as Fusarium oxysporum based upon its cultural and morphological characteristics and internal transcribed spacer (ITS) sequence analysis.

}, issn = {1932-6203}, doi = {10.1371/journal.pone.0071805}, author = {Kumar, Ashutosh and Patil, Deepak and Rajamohanan, Pattuparambil Ramanpillai and Ahmad, Absar} } @article { ISI:000324663100044, title = {Phase, size and shape transformation by fungal biotransformation of bulk TiO2}, journal = {Chemical Engineering Journal}, volume = {230}, year = {2013}, month = {AUG}, pages = {367-371}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Nanosynthesis is an ever expanding frontier in recent years in view of its implications to many future technologies covering diverse fields. Considerable progress has been made realizing high quality synthesis of elemental nanomaterials as well as compounds as chemical, biological and physical routes. The issue of technologically viable large scale synthesis still continues to be a challenge. Here we demonstrate a novel environmentally friendly top down approach to nanosynthesis which exploits the strength and peculiarities of fungus based bioleaching in extracting radicals from compounds and then providing them with a reactive as well as capping environment. Thus protein capped nanoparticles of TiO2 (5-28 nm, circular and brookite phase) are formed directly from micron size (150-250 nm, disc shape, anatase phase) powder by exposing them to a medium of fungus Humicola sp. at just 50 degrees C. The fungus Humicola sp. is not only useful for the synthesis of nanoparticles but also for the transformation of shape, phase and size of TiO2. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {Anatase, Biotransformation, Brookite, humicola sp, TiO2}, issn = {1385-8947}, doi = {10.1016/j.cej.2013.06.091}, author = {Khan, Shadab Ali and Ahmad, Absar} } @article { ISI:000338818800044, title = {Biological synthesis of cationic gold nanoparticles and binding of plasmid DNA}, journal = {Materials Letters}, volume = {129}, year = {2014}, month = {AUG}, pages = {159-161}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Nanobiotechnology is the development of eco-friendly experimental processes for the synthesis of nanomaterials. The present work focuses on synthesis of cationic gold nanoparticles (C-GNPs) for biological applications, especially in gene and drug delivery studies. A biosynthesis methodology has been developed for the functionalization of gold nanoparticles to cationic nature. The synthesis of C-GNPs was done by using peanut leaf extract in the presence of cysteamine. The formed C-GNPs were characterized by using UV-visible spectroscopy (UV-vis), the particles sizes and shapes were confirmed by a Transmission electron microscope (TEM) and crystallinity of C-GNPs was characterized by diffraction. The binding of plasmid DNA on the C-GNPs was confirmed by agarose gel electrophoresis. (C) 2014 Elsevier B.V. All rights reserved.

}, keywords = {Biomaterials, Cationic, Nanoparticles, Plasmid DNA, synthesis, TEM}, issn = {0167-577X}, doi = {10.1016/j.matlet.2014.05.021}, author = {Raju, D. and Vishwakarma, Rishi K. and Khan, Bashir Mohammad and Mehta, Urmil J. and Ahmad, Absar} } @article { ISI:000330241000054, title = {Enzyme mediated synthesis of water-dispersible, naturally protein capped, monodispersed gold nanoparticles; their characterization and mechanistic aspects}, journal = {RSC Advances}, volume = {4}, number = {15}, year = {2014}, month = {JUL}, pages = {7729-7734}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Inorganic nanomaterials are conventionally synthesized under harsh environments like extremes of temperature, pressure and pH. These methods are eco-unfriendly, expensive, toxic, cumbersome, yield bigger particles which agglomerate due to not being capped by capping agents. In contrast, biological synthesis of inorganic nanomaterials occurs under ambient conditions viz. room temperature, atmospheric pressure, physiological pH and is reliable, eco-friendly and cheap. We have already reported the extracellular biosynthesis of monodispersed gold nanoparticles from the whole cells of novel extremophilic actinomycete Thermomonospora sp. In order to know the exact mechanism of synthesis, we decided to investigating it further. Here we describe the simple protocol for purification of the temperature and SDS resistant sulfite reductase enzyme and organic capping molecule, which are required for the synthesis and stabilization of gold nanoparticles respectively. This purified enzyme was then employed for the synthesis of gold nanoparticles along with the capping molecule, which render gold nanoparticles monodispersed in solution.

}, issn = {2046-2069}, doi = {10.1039/c3ra43888k}, author = {Khan, Shadab Ali and Ahmad, Absar} } @article { ISI:000332782600001, title = {Extracellular biosynthesis of gadolinium oxide (Gd2O3) nanoparticles, their biodistribution and bioconjugation with the chemically modified anticancer drug taxol}, journal = {Beilstein Journal of Nanotechnology}, volume = {5}, year = {2014}, month = {MAR}, pages = {249-257}, publisher = {BEILSTEIN-INSTITUT}, type = {Article}, address = {TRAKEHNER STRASSE 7-9, FRANKFURT AM MAIN, 60487, GERMANY}, abstract = {

As a part of our programme to develop nanobioconjugates for the treatment of cancer, we first synthesized extracellular, protein-capped, highly stable and well-dispersed gadolinium oxide (Gd2O3) nanoparticles by using thermophilic fungus Humicola sp. The biodistribution of the nanoparticles in rats was checked by radiolabelling with Tc-99m. Finally, these nanoparticles were bioconjugated with the chemically modified anticancer drug taxol with the aim of characterizing the role of this bioconjugate in the treatment of cancer. The biosynthesized Gd2O3 nanoparticles were characterized by UV-vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS). The Gd2O3-taxol bioconjugate was confirmed by UV-vis spectroscopy and fluorescence microscopy and was purified by using high performance liquid chromatography (HPLC).

}, keywords = {bioconjugation, biodistribution, gadolinium oxide, humicola sp, transmission electron microscopy}, issn = {2190-4286}, doi = {10.3762/bjnano.5.27}, author = {Khan, Shadab Ali and Gambhir, Sanjay and Ahmad, Absar} } @article { ISI:000340292800014, title = {Extracellular biosynthesis of metal sulfide nanoparticles using the fungus fusarium oxysporum}, journal = {Current Nanoscience}, volume = {10}, number = {4}, year = {2014}, month = {JUL}, pages = {588-595}, publisher = {BENTHAM SCIENCE PUBL LTD}, address = {EXECUTIVE STE Y-2, PO BOX 7917, SAIF ZONE, 1200 BR SHARJAH, U ARAB EMIRATES}, abstract = {

The development of reliable, eco-friendly processes for the synthesis of nanomaterials is an important aspect of nanotechnology. One approach that shows immense potential is based on the biosynthesis of nanoparticles using microorganisms such as bacteria. In this report, we demonstrate the extracellular biosynthesis and complete characterization of metal sulfide (PbS, ZnS, MnS and NiS) nanoparticles using fungus, Fusarium oxysporum. We observed that the exposure of aqueous solution of 1 mM metal sulfate to fungus Fusarium oxysporum resulted in the formation of highly stable technologically important metal sulfide semiconductor nanoparticles. Fusarium oxysporum synthesizes lead sulfide and zinc sulfide nanoparticles of fractal type structure whereas manganese sulfide and nickel sulfide nanoparticles are of variable polydispersed morphology. The variable morphology may be due to the dissimilar interaction of metal sulfide nanoparticles with capping proteins secreted by the fungus in solution. The nanoparticles solution is found to be extremely stable with little evidence of aggregation even after a month of storage. The long term stability of the nanoparticles is due to the proteins secreted by fungus in the nanoparticle solution which bind to the surface of the nanoparticles and thus prevent aggregation.

}, keywords = {Biosynthesis, enzymes, fungi, metal sulfide, Nanoparticles}, issn = {1573-4137}, author = {Senapati, Satyajyoti and Syed, Asad and Khan, Shadab and Pasricha, Renu and Khan, Mohammad Islam and Kumar, Rajiv and Ahmad, Absar} } @article {46361, title = {Fungus-mediated preferential bioleaching of waste material such as fly - ash as a means of producing extracellular, protein capped, fluorescent and water soluble silica nanoparticles}, journal = {PLoS One}, volume = {9}, year = {2014}, month = {SEP }, pages = {e107597}, type = {Article}, abstract = {

In this paper, we for the first time show the ability of the mesophilic fungus Fusarium oxysporum in the bioleaching of waste material such as Fly-ash for the extracellular production of highly crystalline and highly stable, protein capped, fluorescent and water soluble silica nanoparticles at ambient conditions. When the fungus Fusarium oxysporum is exposed to Fly-ash, it is capable of selectively leaching out silica nanoparticles of quasi-spherical morphology within 24 h of reaction. These silica nanoparticles have been completely characterized by UV-vis spectroscopy, Photoluminescence (PL), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Energy dispersive analysis of Xrays (EDAX).

}, issn = {1932-6203}, doi = {10.1371/journal.pone.0107597}, author = {Khan, Shadab Ali and Uddin, Imran and Moeez, Sana and Ahmad, Absar} } @article { ISI:000345054100096, title = {Simple recovery of intracellular gold nanoparticles from peanut seedling roots}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {15}, number = {2}, year = {2015}, month = {FEB}, pages = {1575-1581}, publisher = {AMER SCIENTIFIC PUBLISHERS}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

Fabrication of inorganic nanomaterials via a biological route witnesses the formation either extracellularly, intracellulary or both. Whereas extracellular formation of these nanomaterials is cherished owing to their easy and economical extraction and purification processes; the intracellular formation of nanomaterials, due to the lack of a proper recovery protocol has always been dreaded, as the extraction processes used so far were tedious, costly, time consuming and often resulting in very low recovery. The aim of the present study was to overcome the problems related with the extraction and recovery of intracellularly synthesized inorganic nanoparticles, and to devise a method to increasing the output, the shape, size, composition and dispersal of nanoparticles is not altered. Water proved to be much better system as it provided well dispersed, stable gold nanoparticles and higher recovery. This is the first report, where intracellular nanoparticles have been recovered using a very cost-effective and eco-friendly approach.

}, keywords = {gold nanoparticles, Peanut, Recovery, Sonication, Water}, issn = {1533-4880}, doi = {10.1166/jnn.2015.9046}, author = {Raju, D. and Mehta, Urmil J. and Ahmad, Absar} } @article {42555, title = {Biosynthesis of anti-proliferative gold using endophytic fusarium oxysporum strain isolated from neem (A-indica) leaves}, journal = {Current topics in medicinal chemistry}, volume = {16}, year = {2016}, month = {JAN}, pages = {2036-2042}, abstract = {

Here we report a simple, rapid, environment friendly approach for the synthesis of gold nanoparticles using neem (Azadirachta indica A. Juss.) fungal endophyte, which based upon morphological and cultural characteristics was eventually identified as Fusarium oxysporum. The aqueous precursor (HAuCl4) solution when reacted with endophytic fungus resulted in the biosynthesis of abundant amounts of well dispersed gold nanoparticles of 10-40 nm with an average size of 22nm. These biosynthesized gold nanoparticles were then characterized by standard analytical techniques such as UV-Visible spectroscopy, X-ray diffraction, Transmission Electron Microscopy and Fourier Transform Infrared Spectroscopy. Cytotoxic activity of these nanoparticles was checked against three different cell types including breast cancer (ZR-75-1), Daudi (Human Burkitt{\textquoteright}s lymphoma cancer) and normal human peripheral blood mononuclear cells (PBMC), where it was found that our gold nanoparticles are anti-proliferative against cancer cells but completely safe toward normal cells. In addition to this, assessment of toxicity toward human RBC revealed less than 0.1 \% hemolysis as compared to Triton X-100 suggesting safe nature of our biosynthesized gold nanoparticles on human cells. Also, our nanoparticles exhibited no anti-fungal (against Aspergillus niger) or anti-bacterial [against Gram positive (Bacillus subtilis \& Staphylococcus aureus) and Gram negative (Escherichia coli \& Pseudomonas aeruginosa) bacteria] activity thus suggesting their non-toxic, biocompatible nature. The present investigation opens up avenues for eco-friendly, biocompatible nanomaterials to be used in a wide variety of application such as drug delivery, therapeutics, theranostics and so on.

}, doi = {10.2174/1568026616666160215160644}, author = {Siddiqui, Ejaz Ahmad and Ahmad, Absar and Julius, Anju and Syed, Asad and Khan, Shadab and Kharat, Mahesh and Pai, Kalpana and Kadoo, Narendra Y. and Gupta, Vidya} } @article {43634, title = {Biosynthesis of fluorescent Bi2S3 nanoparticles and their application as dual-functionSPECT-CT probe for animal imaging}, journal = {Current Topics In Medicinal Chemistry}, volume = {16}, year = {2016}, month = {OCT}, pages = {2019-2025}, abstract = {Bismuth sulphide (Bi2S3) is an excellent semiconductor and its nanoparticles have numerous significant applications including photovoltaic materials, photodiode arrays, bio-imaging, etc. Nevertheless, these nanoparticles when fabricated by chemical and physical routes tend to easily aggregate in colloidal solutions, are eco-unfriendly, cumbrous and very broad in size distribution. The aim of the present manuscript was to ecologically fabricate water dispersible, safe and stable Bi2S3 nanoparticles such that these may find use in animal imaging, diagnostics, cell labeling and other biomedical applications. Herein, we for the first time have biosynthesized highly fluorescent, natural protein capped Bi2S3 nanoparticles by subjecting the fungus Fusarium oxysporum to bismuth nitrate pentahydrate [Bi(NO3)(3).5H(2)O] alongwith sodium sulphite (Na2SO3) as precursor salts under ambient conditions of temperature, pressure and pH. The nanoparticles were completely characterized using recognized standard techniques. These natural protein capped Bi2S3 nanoparticles are quasi-spherical in shape with an average particle size of 15 nm, maintain long term stability and show semiconductor behavior having blue shift with a band gap of 3.04 eV. Semiconductor nanocrystals are fundamentally much more fluorescent than the toxic fluorescent chemical compounds (fluorophores) which are presently largely employed in imaging, immunohistochemistry, biochemistry, etc. Biologically fabricated fluorescent nanoparticles may replace organic fluorophores and aid in rapid development of biomedical nanotechnology. Thus, biodistribution study of the so-formed Bi2S3 nanoparticles in male Sprague Dawley rats was done by radiolabelling with Technitium-99m (Tc-99m) and clearance time from blood was calculated. The nanoparticles were then employed in SPECT-CT probe for animal imaging where these imparted iodine equivalent contrast.}, doi = {10.2174/1568026616666160215155347}, author = {Uddin, Imran and Ahmad, Absar and Siddiqui, Ejaz Ahmad and Rahaman, Sk. Hasanur and Gambhir, Sanjay} } @article {43624, title = {Nevirapine loaded core shell gold nanoparticles by double emulsion solvent evaporation: invitro and in vivo evaluation}, journal = {Current Drug Delivery}, volume = {13}, year = {2016}, month = {JAN}, pages = {1071-1083}, abstract = {Background: HIV/AIDS is a macrophage resident infection localized in the reticuloendothelial system and remote locations of brain and bone marrow. We present core shell nanoparticles of gold(AuNPs) and nevirapine(NVP) for targeted delivery to the multiple HIV reservoirs. The aim of the study was to design core shell NVP loaded AuNPs with high drug loading and to evaluate biodistribution of the nanoparticles in possible HIV reservoirs in vivo. A specific objective was to assess the possible synergy of AuNPs with NVP on anti-HIV activity in vitro. Method: Core shell nanoparticles were prepared by double emulsion solvent evaporation method and characterized. Results: Glyceryl monostearate-nevirapine-gold nanoparticles(GMS-NVP-AuNPs) revealed high entrapment efficiency (> 70\%), high loading (similar to 40\%), particle size < 250 nm and zeta potential -35.9 +/- 1.41mv and exhibited sustained release with good stability. Surface plasmon resonance indicated shell formation while SEM coupled EDAX confirmed the presence of Au. TEM confirmed formation of spherical core shell nanoparticles. GMS-NVP-AuNPs revealed low hemolysis (< 10 \%) and serum stability upto 6 h. GMS-NVP-AuNPs exhibited rapid, high and sustained accumulation in the possible HIV reservoir organs, including the major organs of liver, spleen, lymph nodes, thymus and also remote locations of brain, ovary and bone marrow. High cell viability and enhanced uptake in PBMC{\textquoteright}s and TZM-bl cells were observed. While uptake in PBMC{\textquoteright}s proposed monocytes/macrophages enabled brain delivery. GMS-NVP-AuNPs demonstrated synergistic anti-HIV activity. Conclusion: The superior anti-HIV activity in vitro coupled with extensive localization of the nanoparticles in multiple HIV reservoirs suggests great promise of the core shell GMS-NVP-AuNPs for improved therapy of HIV.}, doi = {10.2174/1567201813666160114093005}, author = {Dalvi, Bhagyashree R. and Siddiqui, Ejaz A. and Syed, Asad S. and Velhal, Shilpa M. and Ahmad, Absar and Bandivdekar, Atmaram B. and Devarajan, Padma V.} } @article {43962, title = {Effective degradation of organic water pollutants by atmospheric non-thermal plasma torch and analysis of degradation process}, journal = {Chemosphere}, volume = {167}, year = {2017}, month = {JAN}, pages = {396-405}, type = {Article}, abstract = {The paper reports the use of atmospheric non-thermal plasma torch as a catalyst for degradation of various organic pollutants dissolved in water. A flow of He mixed with air was used to produce the dielectric barrier discharge (DBD), at the tip of the torch, using pulsed electric excitation at 12 kV. The torch, operated at a power of 750 mW/mm{\texttwosuperior}, was seen to completely degrade the aqueous solutions of the pollutants namely methylene blue (MB), methyl orange (MO) and rhodamine-B (RB), at around 10$^{-}$$^{4}$ M concentrations, the concentration of polluants is one order higher than of routinely used heterogeneous photocatalytic reactions, within 10 min of irradiation time at room temperature. UV Visible spectra of the organic dye molecules, monitored after different intervals of plasma-irradiation, ranging between 1 and 10 min, have been used as tools to quantify their sequential degradation. Further, instead of using He, only air was used to form plasma plume and used for degradation of organic dye which follow similar trend as that of He plasma. Further, Liquid Chromatography Mass Spectroscopy (LCMS) technique has been used to understand degradation pathway of methylene blue (MB) as a representative case. Total organic carbon (TOC) measurements indicates significant decrease in its content as a function of duration of plasma exposure onto methylene blue as a representative case. Toxicity studies were carried out onto Gram negative Escherichia coli. This indicated that methylene blue, without plasma treatment, shows growth inhibition, whereas with plasma treatment no inhibition was observed.}, doi = {10.1016/j.chemosphere.2016.09.089}, author = {Bansode, Avinash H. and More, Supriya Eknath and Siddiqui, Ejaz Ahmad and Satpute, Shruti and Ahmad, Absar and Bhoraskar, Sudha V. and Mathe, Vikas L.} } @article {43556, title = {Identification of biomolecules involved in the biosynthesis of gold nanoparticles from living peanut seedlings}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {17}, year = {2017}, month = {MAR}, pages = {1787-1795}, abstract = {In present work, we have fabricated gold nanoparticles by treating an aqueous solution of 10(-4) M HAuCl4 with the proteins extracted from roots of in vitro raised peanut seedlings and purified them by FPLC at room temperature. These proteins which tested positive for the reduction of 10(-4) M HAuCl4 were identified as Mannose glucose binding lectin and Ara h 8 allergen isoforms by ESI MS/MS. It is a well known fact that aromatic amino acids possess delocalized pi electrons in their ring structures, rendering them as the best electron donors which can transfer electrons and reduce the acceptor. These results suggest that the aromatic amino acids present in the proteins from the peanut seedlings are the primary biomolecules involved in the reduction of Au (III) to Au (0). We isolated different protein of molecular weight 16.4, 28.3 and 30 kDa involved in the formation of nanoparticles. The protein with molecular weight 16.4 kDa (allergens) yielded NPs of 25-60 nm whereas, the proteins with molecular weight 28.3 kDa and 30 kDa (lectins) yielded highly monodispersed NPs of 5-20 nm in size. The results clearly indicate that the size of nanoparticles can be controlled by different proteins.}, doi = {10.1166/jnn.2017.12879}, author = {Raju, D. and Siddiqui, Ejaz Ahmad and Prasanth, S. and Khan, Bashir M. and Mehta, Urmil J. and Ahmad, Absar} } @article {43807, title = {Nanotubular hard carbon derived from renewable natural seed gel for high performance sodium-ion battery anode}, journal = {Chemistryselect}, volume = {2}, year = {2017}, month = {AUG}, pages = {6909-6915}, type = {Article}, abstract = {

Electrical energy storage devices such as batteries and supercapacitors are perhaps the most researched topic today in view of its critical implications for the successful implementations of various renewable energy harvesting initiatives. Amongst the various battery systems being currently examined, the Li-battery continues to be a main player, but the Na-ion battery has been attracting significant attention lately due to the concerns about the limited reserves and high cost of Li. Hard carbon is recognized to be a good anode material for Na-battery. In this work we present a novel approach to synthesize such hard carbon from a natural gel derived from the commonly used Basil seeds (Osimum Basilicum) which swell 30 times their weight by absorbing water. The hard carbon obtained by pyrolysis of the freeze-dried mucilage possesses sheet-like and tubular morphology with decorated surface defects attributed to the presence of oxygen functionalities. This hard carbon shows a good reversible capacity of 195 mAh g(-1) at 0.1A g(-1) with an impressive approximate to 91\% retention of initial capacity after 300 cycles and sustains high current densities with not much change in capacity value.

}, doi = {10.1002/slct.201701123}, author = {Sharma, Neha and Gawli, Yogesh and Ahmad, Absar and Muhammed, Musthafa and Ogale, Satishchandra} } @article {43863, title = {Size reduction of bulk alumina for mass production of fluorescent nanoalumina by fungus humicola sp.}, journal = {Journal of Cluster Science}, volume = {28}, year = {2017}, month = {JUL}, pages = {1981-1993}, type = {Article}, abstract = {In recent years, nanomaterials have made their way into hundreds of biomedical, life-sciences and technological applications. One such nanomaterial of extreme importance is nanoalumina (Al2O3 nanoparticles). This nanomaterial is an epitome of diversity with applications exhibited in the fields of catalysis, cosmetics, theranostics, energy generation, biosensors, drug-delivery, tumor-regression, etc. However, problems persist in terms of biocompatibility, cost-effectiveness, reproducibility and mass-production of nanoalumina by the presently existent physical, chemical and biological methodologies. Herein, we for the first time are presenting a top-down biofabrication method by which size reduction of commercial bulk alumina/aluminum oxide (5 A mu m) into nanoalumina (5-25 nm) is carried out by a thermophilic fungus Humicola sp. within 96 h of reaction at just 50 A degrees C. The so-formed nanoalumina is highly stable, water dispersible, fluorescent and natural protein capped; characterization engaged standard techniques. These nanoparticles exhibit anti-bacterial properties against Gram-positive Bacillus subtilis strain and may serve as broad spectrum bactericidal agents. We believe that our novel top-down approach may be extensively used in the facile, inexpensive, eco-friendly and reliable fabrication of abundant quantities of nanomaterials of different chemical compositions, sizes and shapes with better control and predictability over the properties as derived from their substrates. The mechanistic aspect of said protocol is underway.}, doi = {10.1007/s10876-017-1195-z}, author = {Moeez, Sana and Siddiqui, Ejaz Ahmad and Khan, Shadab and Ahmad, Absar} } @article {46242, title = {Protein-capped metal nanoparticles inhibit tau aggregation in alzheimer{\textquoteright}s disease}, journal = {Acs Omega}, volume = {4}, year = {2019}, month = {JULY}, pages = {12833-12840}, type = {Article}, abstract = {

The Alzheimer{\textquoteright}s disease (AD) therapeutic research is yielding a large number of potent molecules. The nanoparticle-based therapeutics against the protein aggregation in AD is also taking a lead especially with amyloid-beta as a primary target. In this work, we have screened for the first time protein-capped (PC) metal nanoparticles for their potency in inhibiting Tau aggregation in vitro. We present a novel function of PC-Fe3O4 and PC-CdS nanoparticles as potent Tau aggregation inhibitors by fluorescence spectrometry, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and electron microscopy. We demonstrate that the biologically synthesized PC-metal nanoparticles, especially iron oxide do not affect the viability of neuroblastoma cells. Moreover, PC-CdS nanoparticles show dual properties of inhibition and disaggregation of Tau. Thus, the nanoparticles can take a lead as potent Tau aggregation inhibitors and can be modified for specific drug delivery due to their very small size. The current work presents unprecedented strategy to design anti-Tau aggregation drugs, which provides interesting insights to understand the role of biological nanostructures in Alzheimer{\textquoteright}s disease.

}, doi = {10.1021/acsomega.9b01411}, author = {Sonawane, Shweta Kishor and Ahmad, Absar and Chinnathambi, Subashchandrabose} } @article {47745, title = {Biological synthesis of alpha-Ag2S composite nanoparticles using the fungus Humicola sp. and its biomedical applications}, journal = {Journal of Drug Delivery Science and Technology}, volume = {66}, year = {2021}, month = {DEC}, pages = {102770}, type = {Article}, abstract = {Synthesis of alpha-Ag2S (silver sulfide) is a highly challenging task, usually attempted using synthetic, hazardous chemical processes. This report puts efforts to exploring microbial-based eco-friendly alternatives. A facile, onepot biological method for the synthesis of alpha-Ag2S composite nanoparticles (NPs) in an aqueous medium at ambient conditions was established. As prepared alpha-Ag2S composite NPs were efficiently produced from precursors silver nitrate and sodium sulfite. The extracellular biomolecules produced by Humicola sp. reduced the precursor solution and at the same time it capped the formed Ag2S NPs. The characterization performed by different techniques revealed excellent optical, morphological, and structural properties (size, shape distribution, and crystallinity) of the alpha-Ag2S NPs. The change in color from colorless to dark brown indicated the formation of alpha-Ag2S, which was further confirmed by fluorescence and UV-Visible spectroscopy, showing a sharp peak at 410 nm. Morphological analysis of alpha-Ag2S NPs confirmed the spherical shape, and narrow size distribution. alpha-Ag2S NPs were found to be potent in antimicrobial applications owing to their high dispersibility in water and capping by extracellular biomolecules secreted by Humicola sp. The anti-cancer activity for alpha-Ag2S performed using human breast cancer cell line (ZR-75-1) and human Burkitt{\textquoteright}s lymphoma cancer (Daudi). The biocompatibility test was performed using human peripheral blood mononuclear cells (PBMCs) for alpha-Ag2S NPs. The anti-leishmania activity was also determined for alpha Ag2S NPs in-vitro using the standard anti-promastigote protocol (Leishmania donovani promastigotes). This extracellular system is an economically and environmentally benign route for the biosynthesis of alpha-Ag2S NPs having desired surface, structure and biomedical properties.}, keywords = {Cytotoxicity, Fungus, Hemolysis, Humicolasp, Silver sulfide(alpha-Ag2S)}, issn = {1773-2247}, doi = {10.1016/j.jddst.2021.102770}, author = {Syed, Asad and Saedi, Marzouq Hussain Al and Bahkali, Ali H. and Elgorban, Abdallah M. and Kharat, Maheshkumar and Pai, Kalpana and Ghodake, Gajanan and Ahmad, Absar} } @article {47743, title = {Alpha Au2S nanoparticles: fungal-mediated synthesis, structural characterization and bioassay}, journal = {Green Chemistry Letters and Reviews}, volume = {15}, year = {2022}, month = {JAN }, pages = {59-68}, type = {Article}, abstract = {Luminescent nanoparticles synthesized via bio-based protocols that generate nanoparticles having different chemical compositions along with other functionalities (size and morphology) have received huge attention. We have focused our research on gold sulfide nanoparticles (Au2S NPs) and have biosynthesized these NPs using the fungus Humicola sp. The nanoparticles were characterized by Transmission Electron Microscopy, which showed spherical morphology of Au2S. UV-Visible-NIR spectrophotometry, luminescence spectrophotometry, Selected Area Electron Diffraction, Energy Dispersive Analysis of X-rays, and X-ray diffraction were performed. FTIR confirmed that the fungal metabolites including biomolecules secreted in the reaction medium are primarily responsible for nanoparticle synthesis and stabilization. The fungus reduced the precursor solution (HAuCl4 and Na2SO3) and at the same time capped them with secreted biomolecules. The anti-leishmanial activity of Au2S NPs was determined against L. donovani promastigote (Ag83 strain). Au2S NPs displayed less cytotoxicity towards both normal and cancer (Daudi, ZR-75-1) cell lines. Hemocompatibility was determined via hemolysis assays. This novel fungal-based system demonstrates an economical and environmentally benign process for biosynthesis of Au2S nanoparticles which may find application in bioimaging and labeling studies.}, keywords = {Biosynthesis, Cytotoxicity, Gold sulfide, Hemolysis, humicola sp, promastigote}, issn = {1751-8253}, doi = {10.1080/17518253.2021.1999509}, author = {Syed, Asad and Al Saedi, Marzouq H. and Bahkali, Ali H. and Elgorgan, Abdallah M. and Kharat, Mahesh and Pai, Kalpana and Pichtel, John and Ahmad, Absar} }