02538nas a2200229 4500008004100000245014400041210006900185260000800254300001800262490000700280520158900287653013501876100001802011700002402029700002802053700001802081700002302099700002302122700002102145700001702166856012502183 2012 eng d00aNew chemodosimetric reagents as ratiometric probes for cysteine and homocysteine and possible detection in living cells and in blood plasma0 aNew chemodosimetric reagents as ratiometric probes for cysteine  cNOV a15382–153930 v183 a

In this work, we have rationally designed and synthesized two new reagents (L1 and L2), each bearing a pendant aldehyde functionality. This aldehyde group can take part in cyclization reactions with β- or γ-amino thiols to yield the corresponding thiazolidine and thiazinane derivatives, respectively. The intramolecular charge-transfer (ICT) bands of these thiazolidine and thiazinane derivatives are distinctly different from those of the molecular probes (L1 and L2). Such changes could serve as a potential platform for using L1 and L2 as new colorimetric/fluorogenic as well as ratiometric sensors for cysteine (Cys) and homocysteine (Hcy) under physiological conditions. Both reagents proved to be specific towards Cys and Hcy even in the presence of various amino acids, glucose, and DNA. Importantly, these two chemodosimetric reagents could be used for the quantitative detection of Cys present in blood plasma by using a pre-column HPLC technique. Such examples are not common in contemporary literature. MTT assay studies have revealed that these probes have low cytotoxicity. Confocal laser scanning micrographs of cells demonstrated that these probes could penetrate cell membranes and could be used to detect intracellular Cys/Hcy present within living cells. Thus, the results presented in this article not only demonstrate the efficiency and specificity of two ratiometric chemodosimeter molecules for the quantitative detection of Cys and Hcy, but also provide a strategy for developing reagents for analysis of these vital amino acids in biological samples.

10acharge transfer; chemodosimetric detection; cysteine/ homocysteine sensors; fluorescent probes; imaging agents; ratiometric probes1 aDas, Priyadip1 aMandal, Amal, Kumar1 aChandar, Nellore, Bhanu1 aBaidya, Mithu1 aBhatt, Harshad, B.1 aGanguly, Bishwajit1 aGhosh, Sudip, K.1 aDas, Amitava uhttp://library.ncl.res.in/content/new-chemodosimetric-reagents-ratiometric-probes-cysteine-and-homocysteine-and-possible00988nas a2200205 4500008004100000022001400041245012900055210006900184260011000253300001400363490000700377520015100384100002300535700002100558700001500579700002100594700002300615700001700638856012700655 2013 eng d a1359-734500aNew receptor with a FRET based fluorescence response for selective recognition of fumaric and maleic acids in aqueous medium0 aNew receptor with a FRET based fluorescence response for selecti aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG a9818-98200 v493 a

Preferential binding of a new reagent to fumaric acid could be utilized for its estimation in aqueous medium and in commercial fruit juice.

1 aReddy, Upendar, G.1 aLo, Rabindranath1 aRoy, Sovan1 aBanerjee, Tanmay1 aGanguly, Bishwajit1 aDas, Amitava uhttp://library.ncl.res.in/content/new-receptor-fret-based-fluorescence-response-selective-recognition-fumaric-and-maleic-002181nas a2200205 4500008004100000022001400041245016400055210006900219260011000288300001600398490000700414520129900421100002101720700002401741700002401765700002301789700001701812700002601829856012001855 2014 eng d a1477-922600aNew Ru(II)/Os(II)-polypyridyl complexes for coupling to TiO2 surfaces through acetylacetone functionality and studies on interfacial electron-transfer dynamics0 aNew RuIIOsIIpolypyridyl complexes for coupling to TiO2 surfaces  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a13601-136110 v433 a

New Ru(II)- and Os(II)-polypyridyl complexes have been synthesized with pendant acetylacetone (acac) functionality for anchoring on nanoparticulate TiO2 surfaces with a goal of developing an alternate sensitizer that could be utilized for designing an efficient dye-sensitized solar cell (DSSC). Time-resolved transient absorption spectroscopic studies in the femtosecond time domain have been carried out. The charge recombination rates are observed to be very slow, compared with those for strongly coupled dye molecules having catechol as the anchoring functionality. The results of such studies reveal that electron-injection rates from the metal complex-based LUMO to the conduction band of TiO2 are faster than one would expect for an analogous complex in which the chromophoric core and the anchoring moiety are separated with multiple saturated C-C linkages. Such an observation is rationalized based on computational studies, and a relatively smaller spatial distance between the dye LUMO and the TiO2 surface accounted for this. Results of this study are compared with those for analogous complexes having a gem-dicarboxy group as the anchoring functionality for covalent binding to the TiO2 surface to compare the role of binding functionalities on electron-transfer dynamics.

1 aBanerjee, Tanmay1 aBiswas, Abul, Kalam1 aSahu, Tuhin, Subhra1 aGanguly, Bishwajit1 aDas, Amitava1 aGhosh, Hirendra, Nath uhttp://library.ncl.res.in/content/new-ruiiosii-polypyridyl-complexes-coupling-tio2-surfaces-through-acetylacetone-0