@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: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: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: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: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: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: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: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} }