01186nas a2200193 4500008004100000245012700041210006900168260000800237300001400245490000800259520048300267100001800750700001800768700001700786700002100803700002300824700001700847856012800864 2011 eng d00aDiamine derivative of a ruthenium(II)-polypyridyl complex for chemodosimetric detection of nitrite ion in aqueous solution0 aDiamine derivative of a rutheniumIIpolypyridyl complex for chemo cFEB a115–1190 v3723 a

Nitrite is quite an abundant anion in the environment. It, however, becomes toxic to human life, as well as aquatic animals when present above the permissible concentration level. We have reported here a Ru(II)-polypyridyl-based complex (1) for chemodosimetric detection of nitrite ion in aqueous solution. Formation of the new triazole based complex, generated by reaction of 1 and N2O3, is ascertained by comparing its properties with a presynthesised triazole complex.

1 aGhosh, Amrita1 aDas, Priyadip1 aSaha, Sukdeb1 aBanerjee, Tanmay1 aBhatt, Harshad, B.1 aDas, Amitava uhttps://library.ncl.res.in/content/diamine-derivative-rutheniumii-polypyridyl-complex-chemodosimetric-detection-nitrite-ion00770nas a2200169 4500008004100000245009500041210006900136260000800205300001600213490000700229520016400236100002200400700001700422700002100439700001700460856012300477 2011 eng d00aSolvent-dependent aggregation behavior of a new Ru(ii)-polypyridyl based metallosurfactant0 aSolventdependent aggregation behavior of a new Ruiipolypyridyl b cSEP a11074-110760 v473 a

Variation of the solvent polarity leads to the formation of vesicles and reverse vesicles of a newly synthesized amphiphilic Ru(II)-polypyridyl complex.

1 aMahato, Prasenjit1 aSaha, Sukdeb1 aChoudhury, Sipra1 aDas, Amitava uhttps://library.ncl.res.in/content/solvent-dependent-aggregation-behavior-new-ruii-polypyridyl-based-metallosurfactant01715nas a2200205 4500008004100000245010600041210006900147260000800216300001400224490000800238520099700246100001801243700002201261700001801283700002401301700002101325700001701346700001701363856012901380 2011 eng d00aUrea/thiourea derivatives and Zn(II)-DPA complex as receptors for anionic recognition-a brief account0 aUreathiourea derivatives and ZnIIDPA complex as receptors for an cOCT a175–1860 v1233 a

This review covers few examples of anion complexation chemistry, with a special focus on urea/thiourea-based receptors and Zn(II)-dipicolyl amine-based receptors. This article specially focuses on structural aspects of the receptors and the anions for obtaining the desire specificity along with an efficient receptor–anion interaction. Two types of receptors have been described in this brief account; first one being the strong hydrogen bond donor urea/thiourea derivatives, which binds the anionic analytes through hydrogen bonded interactions; while, the second type of receptors are coordination complexes, where the coordination of the anion to the metal centre. In both the cases the anion binding modulate the energy gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and thereby the spectroscopic response. Appropriate choice of the signalling unit may allow probing the anion binding phenomena through visual detection.

1 aDas, Priyadip1 aMahato, Prasenjit1 aGhosh, Amrita1 aMandal, Amal, Kumar1 aBanerjee, Tanmay1 aSaha, Sukdeb1 aDas, Amitava uhttps://library.ncl.res.in/content/ureathiourea-derivatives-and-znii-dpa-complex-receptors-anionic-recognition-brief-account02275nas a2200169 4500008004100000245016000041210006900201260000800270300001600278490000700294520159700301100002201898700001701920700002101937700001701958856013001975 2012 eng d00aInterfacial and film formation behavior of photoactive Ru(ii)bipyridyl based metallosurfactants and a rare example of a monolayer based logic gate approach0 aInterfacial and film formation behavior of photoactive Ruiibipyr cDEC a1096–11050 v773 a

Three derivatives of tris(bipyridyl)–ruthenium(II) complexes with different alkyl-chain lengths (nC18H37 (1), nC14H29 (2) and nC10H21 (3)) were synthesised. All these complexes behaved as an amphiphile and their surface properties were studied at the air–water interface by measuring surface pressure–area (Π–A) isotherms. The surface morphology of the resulting films at the air–water interface was also studied by using Brewster angle microscopy. Mean molecular areas of these complexes were measured from the Π–A isotherms, which were approximately 200 Å2, thereby indicating a parallel arrangement of the Ru–bipyridyl moiety of the complexes. Mono- and multilayer Langmuir–Blodgett (LB) films were formed on different solid surfaces with transfer ratios close to one. Similarities in the absorption and fluorescence spectra of these amphiphiles in solution as well as in LB films deposited on a quartz surface confirmed the successful transfer of these films onto the substrates. The latter provided information about the arrangements of metallosurfactant molecules within the LB films. The two-dimensional concentrations of these films were calculated from the Lambert–Beer law as well as from the Π–A isotherm, which confirmed regular and reproducible transfer of the complex monolayers from the air–water interface onto the quartz surface. The surface morphology of these films on various substrates was characterised by atomic force microscopy. Furthermore, by oxidising the monolayer of complex 3, a one-input sequential logic gate was constructed.

1 aMahato, Prasenjit1 aSaha, Sukdeb1 aChoudhury, Sipra1 aDas, Amitava uhttps://library.ncl.res.in/content/interfacial-and-film-formation-behavior-photoactive-ruiibipyridyl-based-metallosurfactants00937nas a2200181 4500008004100000245013400041210006900175260000800244300001400252490000700266520026000273100001700533700002200550700001800572700002100590700001700611856012700628 2012 eng d00aInterrupted PET coupled TBET process for the design of a specific receptor for Hg2+ and its intracellular detection in MCF7 cells0 aInterrupted PET coupled TBET process for the design of a specifi cJUL a9293-92950 v483 a

A new coumarin–rhodamine conjugate constitutes a unique example of the interrupted PET coupled TBET response for developing an imaging reagent for determining the intracellular distribution of Hg2+ in MCF7 cells exposed to [Hg2+] as low as 2 ppb.

1 aSaha, Sukdeb1 aMahato, Prasenjit1 aBaidya, Mithu1 aGhosh, Sudip, K.1 aDas, Amitava uhttps://library.ncl.res.in/content/interrupted-pet-coupled-tbet-process-design-specific-receptor-hg2-and-its-intracellular01981nas a2200157 4500008004100000245017200041210006900213260000800282300001800290490000800308520132800316100002201644700001701666700001701683856012301700 2012 eng d00aRare example of TICT based optical responses for the specific recognition of Cr3+ by a 2,2?:6?,2?-terpyridine derivative and demonstration of multiple logic operations0 aRare example of TICT based optical responses for the specific re cJUL a17448–174570 v1163 a

Chemosensor L showed a nonlinear fluorescence response on specific binding to Cr3+ ion in the presence of various alkali, alkaline-earth, transition, and lanthanide metal ions. A luminescence band with maxima at 512 nm for L was observed (λext = 330 nm) for a twisted intramolecular charge transfer (TICT) transition following antienergy gap law behavior. However, normal energy gap law behavior prevailed on formation of a new nonluminescent charge transfer complex, Mn+·L. For paramagnetic metal ions, paramagnetism induced luminescence quenching could have also contributed to this. A new switched on fluorescence response at λems of 356 nm (λext of 330 nm) was observed due to Franck–Condon charge transfer (FC-CT) transition only on the formation of a complex, (Cr3+)2·L. Spectral studies revealed a unique dynamic coordination behavior and migration of Cr3+ from the terpyridyl fragment to the NNMe2 center of L as a function of the varying concentration of another ion (Zn2+) and the subtle difference in the binding affinities of the terpyridyl moiety toward Cr3+ and Zn2+. Further, spectral responses of L toward Zn2+, different concentration of Cr3+, H+ and on subsequent addition of F– as different ionic inputs could be correlated well for demonstrating various basic and combinatorial circuits.

1 aMahato, Prasenjit1 aSaha, Sukdeb1 aDas, Amitava uhttps://library.ncl.res.in/content/rare-example-tict-based-optical-responses-specific-recognition-cr3-2262-terpyridine01765nas a2200229 4500008004100000245009600041210006900137260000800206300001600214490000700230520098300237100002201220700001701242700001501259700001901274700002801293700002701321700002601348700002301374700001701397856012101414 2012 eng d00aRatiometric detection of Cr3+ and Hg2+ by a naphthalimide-rhodamine based fluorescent probe0 aRatiometric detection of Cr3 and Hg2 by a naphthalimiderhodamine cJAN a1769–17770 v513 a

Newly synthesized rhodamine derivatives, L1 and L2, are found to bind specifically to Hg2+ or Cr3+ in presence of large excess of other competing ions with associated changes in their optical and fluorescence spectral behavior. These spectral changes are significant enough in the visible region of the spectrum and thus, allow the visual detection. For L1, the detection limit is even lower than the permissible [Cr3+] or [Hg2+] in drinking water as per standard U.S. EPA norms; while the receptor, L2 could be used as a ratiometric sensor for detection of Cr3+ and Hg2+ based on the resonance energy transfer (RET) process involving the donor naphthalimide and the acceptor Cr3+/Hg2+-bound xanthene fragment. Studies reveal that these two reagents could be used for recognition and sensing of Hg2+/Cr3+. Further, confocal laser microscopic studies confirmed that the reagent L2 could also be used as an imaging probe for detection of uptake of these ions in A431 cells.

1 aMahato, Prasenjit1 aSaha, Sukdeb1 aSuresh, E.1 aDi Liddo, Rosa1 aParnigotto, Pier, Paolo1 aConconi, Maria, Teresa1 aKesharwani, Manoj, K.1 aGanguly, Bishwajit1 aDas, Amitava uhttps://library.ncl.res.in/content/ratiometric-detection-cr3-and-hg2-naphthalimide-rhodamine-based-fluorescent-probe01954nas a2200217 4500008004100000245014700041210006900188260000800257300001400265490000700279520116100286100001701447700002201464700002301486700001501509700002501524700001801549700002101567700001701588856013101605 2012 eng d00aRecognition of Hg 2+ and Cr 3+ in physiological conditions by a rhodamine derivative and its application as a reagent for cell-imaging studies0 aRecognition of Hg 2 and Cr 3 in physiological conditions by a rh cDEC a336–3450 v513 a

A new rhodamine-based receptor, derivatized with an additional fluorophore (quinoline), was synthesized for selective recognition of Hg2+ and Cr3+ in an acetonitrile/HEPES buffer medium of pH 7.3. This reagent could be used as a dual probe and allowed detection of these two ions by monitoring changes in absorption and the fluorescence spectral pattern. In both instances, the extent of the changes was significant enough to allow visual detection. More importantly, the receptor molecule could be used as an imaging reagent for detection of Hg2+ and Cr3+ uptake in live human cancer cells (MCF7) using laser confocal microscopic studies. Unlike Hg(ClO4)2 or Hg(NO3)2 salts, HgCl2 or HgI2 failed to induce any visually detectable change in color or fluorescence upon interaction with L1 under identical experimental conditions. Presumably, the higher covalent nature of HgII in HgCl2 or HgI2 accounts for its lower acidity and its inability to open up the spirolactam ring of the reagent L1. The issue has been addressed on the basis of the single-crystal X-ray structures of L1·HgX2 (X– = Cl– or I–) and results from other spectral studies.

1 aSaha, Sukdeb1 aMahato, Prasenjit1 aReddy, Upendar, G.1 aSuresh, E.1 aChakrabarty, Arindam1 aBaidya, Mithu1 aGhosh, Sudip, K.1 aDas, Amitava uhttps://library.ncl.res.in/content/recognition-hg-2-and-cr-3-physiological-conditions-rhodamine-derivative-and-its-application00902nas a2200193 4500008004100000245013700041210006900178260000800247300001400255490000700269520018100276100001700457700002500474700002200499700001600521700002200537700001700559856013200576 2012 eng d00aRhodamine-alginate conjugate as self-indicating gel beads for efficient detection and scavenging of Hg 2+ and Cr 3+ in aqueous media0 aRhodaminealginate conjugate as selfindicating gel beads for effi cNOV a1659-16610 v483 a

Effective extraction of Hg2+ and Cr3+ ions from aqueous media by novel rhodamine–alginate polymer-based highly fluorogenic, as well as colorimetric, chemosensor beads.

1 aSaha, Sukdeb1 aChhatbar, Mahesh, U.1 aMahato, Prasenjit1 aPraveen, L.1 aSiddhanta, A., K.1 aDas, Amitava uhttps://library.ncl.res.in/content/rhodamine-alginate-conjugate-self-indicating-gel-beads-efficient-detection-and-scavenging-hg00928nas a2200193 4500008004100000245011800041210006900159260000800228300001200236490000700248520023900255100002300494700001800517700001700535700001800552700002100570700001700591856012600608 2013 eng d00aCN? specific turn-on phosphorescent probe with probable application for enzymatic assay and as an imaging reagent0 aCN specific turnon phosphorescent probe with probable applicatio cOCT a255-2570 v493 a

A new “turn-on” luminescence probe for imaging the uptake of 0.2 ppm inorganic CN− in live HeLa cells as well as for probing the CN− generation through an enzymatic process in a virtual aqueous medium at appropriate pH.

1 aReddy, Upendar, G.1 aDas, Priyadip1 aSaha, Sukdeb1 aBaidya, Mithu1 aGhosh, Sudip, K.1 aDas, Amitava uhttps://library.ncl.res.in/content/cn-specific-turn-phosphorescent-probe-probable-application-enzymatic-assay-and-imaging01771nas a2200217 4500008004100000022001400041245013700055210006900192260011000261300001600371490000700387520090800394100001701302700002301319700001801342700001801360700001501378700002101393700001701414856012201431 2013 eng d a1477-922600aNew chemodosimetric probe for the specific detection of Hg2+ in physiological condition and its utilisation for cell imaging studies0 aNew chemodosimetric probe for the specific detection of Hg2 in p aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL a15097-151050 v423 a

A dithiane derivative of BODIPY is synthesized. This new reagent could be used for the specific and instantaneous detection of Hg2+ in physiological condition. This dithiane reagent reacts specifically with Hg2+ to regenerate the parent BODIPY-aldehyde with consequential change in visually detectable optical responses and this provides the possibility of using this reagent as a colorimetric probe or as a fluorescent biomarker/imaging reagent. Further, non-covalent interactions could be utilized for formation of an inclusion complex with biologically benign beta-cyclodextrin for enhancing its solubility in aqueous environment and this included adduct could be used as a fluorescent marker and imaging reagent for Hg2+. Uptake of Hg2+ ions in live HeLa cells, exposed to a solution having Hg2+ ion concentration as low as 2 ppb, could also be detected by confocal laser microscopic studies.

1 aSaha, Sukdeb1 aAgarwalla, Hridesh1 aGupta, Hariom1 aBaidya, Mithu1 aSuresh, E.1 aGhosh, Sudip, K.1 aDas, Amitava uhttps://library.ncl.res.in/content/new-chemodosimetric-probe-specific-detection-hg2-physiological-condition-and-its-001761nas a2200169 4500008004100000245013500041210006900176260000800245300001400253490000600267520111800273100001601391700001701407700002501424700001701449856012501466 2013 eng d00aSelf-assembly of modified rhodamine-6G with tri-block copolymer: unusual vesicles formation, pH sensing and dye release properties0 aSelfassembly of modified rhodamine6G with triblock copolymer unu cDEC a1150-11550 v13 a

A new rhodamine-6G derivative having a C18-alkyl chain self-assembles with an amphiphilic tri-block copolymer and forms stable vesicles in water or in water–ethanol (4 : 1, v/v) medium. The stability of the spirolactam form of the rhodamine-6G derivative in these vesicular structures, along with studies of controlled dye release and pH sensing are discussed. Transmission electron micrographs and DLS analyses confirm the formation of vesicular structures. Atomic force microscopy (AFM) images show that the self assembled tri-block copolymer-octadecyl rhodamine vesicles form near spherical nanostructures with a size ranging from 80 to 110 nm. Furthermore, the vesicular system is disassembled under acidic conditions, releasing the cargo which are an integral part of the vesicle. Dye-release studies showed that the release rates of the loaded dye in the vesicles could be well-controlled as a function of the media pH. These results offer an opportunity to use these nanovesicles as imaging reagents for probing media pH with their simultaneous use as nanocarriers for intracellular drug delivery.

1 aPraveen, L.1 aSaha, Sukdeb1 aJewrajka, Suresh, K.1 aDas, Amitava uhttps://library.ncl.res.in/content/self-assembly-modified-rhodamine-6g-tri-block-copolymer-unusual-vesicles-formation-ph02568nas a2200193 4500008004100000022001400041245006000055210005900115260011000174300001600284490000600300520188500306100002202191700001702213700001802230700002302248700001702271856008602288 2014 eng d a2046-206900aOverview of the recent developments on Hg2+ recognition0 aOverview of the recent developments on Hg2 recognition aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUN a36140-361740 v43 a

Adverse influences of mercury on living organisms are well known. Despite efforts from various regulatory agencies, the build-up of Hg2+ concentration in the environment is of serious concern. This necessitates the search for new and efficient reagents for recognition and detection of Hg2+ in environmental samples as well as for application in diagnostics. Among various detection processes adopted for designing such reagents, generally methodologies that allow associated changes in spectra properties are preferred for the obvious ease in the detection process. Significant changes in the electronic spectral pattern in the visible region of the spectrum also induce detectable changes in solution colour for naked-eye detection and are useful for developing reagents for in-field sample analysis with yes-no type binary responses. However, reagents that allow detection of Hg2+ with associated fluorescence on response are useful for detection of Hg2+ in environmental samples, as well as for use as an imaging reagent, for detection of cellular uptake. High spin-orbit coupling constant for Hg2+ along with its high solvation energy in aqueous medium poses a challenge in developing efficient reagents with fluorescence on response that work in aqueous medium/physiological condition. To get around this problem, several methodologies, like conversion of rhodamine derivative spirolactam to strongly fluorescent xanthenes that form on binding to Hg2+, chemodosimetric reaction for generation of a new luminescent derivative, have been adopted. Apart from these, modified charge transfer processes on binding to Hg2+ have also been utilized for designing reagents for optical detection of Hg2+. Immobilization of such reagents on solid surfaces also led to the development of self-indicating Hg2+ ion scavengers. All such examples are discussed in the present review.

1 aMahato, Prasenjit1 aSaha, Sukdeb1 aDas, Priyadip1 aAgarwalla, Hridesh1 aDas, Amitava uhttps://library.ncl.res.in/content/overview-recent-developments-hg2-recognition-002501nas a2200193 4500008004100000022001400041245009100055210006900146260011000215300001600325490000700341520174100348100001802089700002202107700001702129700002702146700001702173856011702190 2015 eng d a1463-907600aRapid conductometric sensor for the analysis of cyanide using imidazole based receptor0 aRapid conductometric sensor for the analysis of cyanide using im aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a26790-267960 v173 a

A specific and efficient hydrogen bonding interaction between cyanide and the HN-H [imidazole] in an aqueous medium has been utilized for the selective recognition of cyanide under physiological conditions. The possibility of utilizing such an interaction for developing any practical device for the specific detection of cyanide in an aqueous environment has not been explored to date. We now report a simple dip and read conductometric sensor for cyanide ions using a tailored electrode in aqueous media. The purpose built reagent, 2-phenyl-1H-anthra-[2,3-d]-immidazole-5,10 dione was immobilized in a polyaniline matrix to fabricate this conductometric device. The homogeneous immobilization of the receptor in polyaniline was confirmed by FT-IR mapping. The proposed transduction mechanism is charge neutralization on the polyaniline moiety, which ultimately inhibits the protonation resulting in a decrease in the conductance of polyaniline. The sensor response was measured in three ranges of cyanide concentration (10(-10) M to 10(-8) M; 10(-8) M to 10(-6) M and 10(-6) M to 10(-3) M). Whereas the device is found insensitive in the first range, it acts as a detector in the second range and as a proportional sensor in the third range. The minimum detection limit of this device was found to be 10 nmol L-1 (2.6 ppt), which is significantly less than the WHO guideline values. The responses have been investigated under various conditions such as different pH and the electrochemical state of the polymer. The current device has been found to be better close to neutral pH and at a 400 mV vs. Ag/AgCl potential. The reproducibility and repeatability of the sensor was investigated and interference studies were performed.

1 aPaul, Anirban1 aPerween, Mosarrat1 aSaha, Sukdeb1 aSrivastava, Divesh, N.1 aDas, Amitava uhttps://library.ncl.res.in/content/rapid-conductometric-sensor-analysis-cyanide-using-imidazole-based-receptor-002773nas a2200241 4500008004100000022001400041245011700055210006900172260007100241300001600312490000800328520190000336100001502236700001702251700001902268700001902287700002202306700001502328700002302343700002502366700001702391856012302408 2015 eng d a1520-610600aSpecific reagent for Cr(III): imaging cellular uptake of Cr(III) in Hct116 cells and theoretical rationalization0 aSpecific reagent for CrIII imaging cellular uptake of CrIII in H a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a13018-130260 v1193 a

A new rhodamine-based reagent (L-1), trapped inside the micellar structure of biologically benign Triton-X 100, could be used for specific recognition of Cr(III) in aqueous buffer medium having physiological pH. This visible light excitable reagent on selective binding to Cr(III) resulted in a strong fluorescence turn-on response with a maximum at similar to 583 nm and tail of that luminescence band extended until 650 nm, an optical response that is desired for avoiding the cellular autofluorescence. Interference studies confirm that other metal ions do not interfere with the detection process of Cr(III) in aqueous buffer medium having pH 7.2. To examine the nature of binding of Cr(III) to L-1, various spectroscopic studies are performed with the model reagent L-1 which tend to support Cr(III)-eta(2)-olefin pi-interactions involving two olefin bonds in molecular probe L-1. Computational studies are also performed with another model reagent L-M to examine the possibility of such Cr(III)-eta(2)-olefin pi-interactions. Presumably, polar functional groups of the model reagent L-M upon coordination to the Cr(III) center effectively reduce the formal charge on the metal ion and this is further substantiated by results of the theoretical studies. This assembly is found to be cell membrane permeable and shows insignificant toxicity toward live colon cancer cells (Hct116). Confocal laser scanning microscopic studies further revealed that the reagent L-1 could be used as an imaging reagent for detection of cellular uptake of Cr(III) in pure aqueous buffer medium by Hct116 cells. Examples of a specific reagent for paramagnetic Cr(III) with luminescence ON response are scanty in the contemporary literature. This ligand design helped us in achieving the turn on response by utilizing the conversion from spirolactam to an acyclic xanthene form on coordination to Cr(III).

1 aAli, Firoj1 aSaha, Sukdeb1 aMaity, Arunava1 aTaye, Nandaraj1 aSi, Mrinal, Kanti1 aSuresh, E.1 aGanguly, Bishwajit1 aChattopadhyay, Samit1 aDas, Amitava uhttps://library.ncl.res.in/content/specific-reagent-criii-imaging-cellular-uptake-criii-hct116-cells-and-theoretical-0