Swapnadip Roy | National Institute of Technology, Durgapur (original) (raw)
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Papers by Swapnadip Roy
Journal of Luminescence, 2012
The synthesis and solvatochromic behavior of the compound, 7-oxy(5-selenocyanato-pentyl)-2H-1benz... more The synthesis and solvatochromic behavior of the compound, 7-oxy(5-selenocyanato-pentyl)-2H-1benzopyran-2-one (PCM), a pervasive, bioactive coumarin derivative, which is expected to possess antioxidative properties and other important therapeutic activities of significant potency with low systematic toxicity, have been reported employing steady state and time resolved fluorescence techniques. Spectroscopic studies reveal that the solvatochromic behavior of the probe depends not only on the polarity of the medium but also on the hydrogen bonding properties of the solvents. Specific hydrogen bonding interaction of PCM in polar solvents modulated the order of the two closelying lowest singlet states. The photophysical response of PCM in different solvents has been explained considering solute-solvent interactions. To corroborate these results, we performed the ground-state geometry, lowest energy transition and the UV-vis spectrum of PCM using the density functional theory (DFT) and the time-dependent density functional theory (TD-DFT) at B3LYP/6-31G n level. We found excellent correlation between the predicted and experimental spectral data, providing a useful tool in the design of new fluorogenic probes having potential therapeutic activity.
The physiological importance of bile salts lies in their ability to solubilise cholesterol, dieta... more The physiological importance of bile salts lies in their ability to solubilise cholesterol, dietary lipids and fat soluble vitamins in the gastrointestinal tract. The detergent action of bile salts is mainly due to their micelle-forming capacity hence these are known as “biosurfactants”. Owing to its physiological importance, proper understanding of the micellisation process of bile salts is essential in the evaluation of their biological activities. The sensitivity of a fluorescent molecule to its immediate environment makes fluorescence a versatile technique to be used for acquiring important information about micelles and micellisation process. 1,6-Diphenylhexatriene (DPH) is one of the most sensitive fluorescent probes used for such studies. Using the fluorescence intensity of DPH, CMC of sodium taurocholate and sodium taurodeoxycholate was evaluated and found to be 17 mM and 7 mM, respectively. It was found that the fluorescence intensity of DPH in cholate micelles is less than...
Journal of Scientific Enquiry
The distribution of mercury and its compounds has an adverse effect to the living system. However... more The distribution of mercury and its compounds has an adverse effect to the living system. However, among all the mercury species organic mercury is the most hazardous to the living beings. In this review article we are trying to canvass the article from the last two decades on sensitive and cost effective method to detect and/or sensing trace amount of mercury using optically active nanomaterials by colorimetric, fluorimetric and surface enhanced Raman spectrometric method.
Journal of Photochemistry and Photobiology A: Chemistry
New Journal of Chemistry
A new simple 3-in-1 multi-response thiosemicarbazone-based chemosensor has been synthesized and c... more A new simple 3-in-1 multi-response thiosemicarbazone-based chemosensor has been synthesized and characterized.
Sensors and Actuators B: Chemical
Journal of Fluorescence, 2013
A rhodamine B-based fluorescence probe (1) for the sensitive and selective detection of Cu(2+) io... more A rhodamine B-based fluorescence probe (1) for the sensitive and selective detection of Cu(2+) ion has been designed and synthesized using pyridine moiety. The optical properties of this compound have been investigated in acetonitrile-water binary solution (7:3 v/v). Compound 1 is found to be an excellent sensor for a biologically/physiologically very important transition metal ion (Cu(2+)) using only the two very different modes of measurements (absorption and emission); one case displayed intensity enhancement whereas in other case showed intensity depletion (quenching). A mechanistic investigation has been performed to explore the static nature of quenching process. The sensor has been found to be very effective in sensing Cu(2+) ion inside living cells also.
An "off-on" rhodamine-based fluorescence probe for the selective signaling of Cu(II) and Fe(III) ... more An "off-on" rhodamine-based fluorescence probe for the selective signaling of Cu(II) and Fe(III) has been designed and synthesized. The optical properties of this compound have been investigated in acetonitrile-water (1:1) binary solution. Very interestingly, this compound showed sensitivity and selectivity towards Cu(II) during absorption process and towards Fe(III) during emission process. So this is a nice example of an excellent dual chemosensor for two biologically/physiologically very important transition metal ions using only the two very different techniques (absorption and emission); both cases displayed only intensity enhancement.
Journal of Luminescence, 2012
The synthesis and solvatochromic behavior of the compound, 7-oxy(5-selenocyanato-pentyl)-2H-1benz... more The synthesis and solvatochromic behavior of the compound, 7-oxy(5-selenocyanato-pentyl)-2H-1benzopyran-2-one (PCM), a pervasive, bioactive coumarin derivative, which is expected to possess antioxidative properties and other important therapeutic activities of significant potency with low systematic toxicity, have been reported employing steady state and time resolved fluorescence techniques. Spectroscopic studies reveal that the solvatochromic behavior of the probe depends not only on the polarity of the medium but also on the hydrogen bonding properties of the solvents. Specific hydrogen bonding interaction of PCM in polar solvents modulated the order of the two closelying lowest singlet states. The photophysical response of PCM in different solvents has been explained considering solute-solvent interactions. To corroborate these results, we performed the ground-state geometry, lowest energy transition and the UV-vis spectrum of PCM using the density functional theory (DFT) and the time-dependent density functional theory (TD-DFT) at B3LYP/6-31G n level. We found excellent correlation between the predicted and experimental spectral data, providing a useful tool in the design of new fluorogenic probes having potential therapeutic activity.
The physiological importance of bile salts lies in their ability to solubilise cholesterol, dieta... more The physiological importance of bile salts lies in their ability to solubilise cholesterol, dietary lipids and fat soluble vitamins in the gastrointestinal tract. The detergent action of bile salts is mainly due to their micelle-forming capacity hence these are known as “biosurfactants”. Owing to its physiological importance, proper understanding of the micellisation process of bile salts is essential in the evaluation of their biological activities. The sensitivity of a fluorescent molecule to its immediate environment makes fluorescence a versatile technique to be used for acquiring important information about micelles and micellisation process. 1,6-Diphenylhexatriene (DPH) is one of the most sensitive fluorescent probes used for such studies. Using the fluorescence intensity of DPH, CMC of sodium taurocholate and sodium taurodeoxycholate was evaluated and found to be 17 mM and 7 mM, respectively. It was found that the fluorescence intensity of DPH in cholate micelles is less than...
Journal of Scientific Enquiry
The distribution of mercury and its compounds has an adverse effect to the living system. However... more The distribution of mercury and its compounds has an adverse effect to the living system. However, among all the mercury species organic mercury is the most hazardous to the living beings. In this review article we are trying to canvass the article from the last two decades on sensitive and cost effective method to detect and/or sensing trace amount of mercury using optically active nanomaterials by colorimetric, fluorimetric and surface enhanced Raman spectrometric method.
Journal of Photochemistry and Photobiology A: Chemistry
New Journal of Chemistry
A new simple 3-in-1 multi-response thiosemicarbazone-based chemosensor has been synthesized and c... more A new simple 3-in-1 multi-response thiosemicarbazone-based chemosensor has been synthesized and characterized.
Sensors and Actuators B: Chemical
Journal of Fluorescence, 2013
A rhodamine B-based fluorescence probe (1) for the sensitive and selective detection of Cu(2+) io... more A rhodamine B-based fluorescence probe (1) for the sensitive and selective detection of Cu(2+) ion has been designed and synthesized using pyridine moiety. The optical properties of this compound have been investigated in acetonitrile-water binary solution (7:3 v/v). Compound 1 is found to be an excellent sensor for a biologically/physiologically very important transition metal ion (Cu(2+)) using only the two very different modes of measurements (absorption and emission); one case displayed intensity enhancement whereas in other case showed intensity depletion (quenching). A mechanistic investigation has been performed to explore the static nature of quenching process. The sensor has been found to be very effective in sensing Cu(2+) ion inside living cells also.
An "off-on" rhodamine-based fluorescence probe for the selective signaling of Cu(II) and Fe(III) ... more An "off-on" rhodamine-based fluorescence probe for the selective signaling of Cu(II) and Fe(III) has been designed and synthesized. The optical properties of this compound have been investigated in acetonitrile-water (1:1) binary solution. Very interestingly, this compound showed sensitivity and selectivity towards Cu(II) during absorption process and towards Fe(III) during emission process. So this is a nice example of an excellent dual chemosensor for two biologically/physiologically very important transition metal ions using only the two very different techniques (absorption and emission); both cases displayed only intensity enhancement.