Development of Potential Strategies from Traditional Understandings

<strong>Seminar of the School of Physical Sciences -------------------------------------------------</strong> Title: <strong>Development of Potential Strategies from Traditional Understandings</strong> Speaker: <strong>Nitin Chattopadhyay</strong> (Jadavpur University, Kolkata) Date: <strong>December 4, 2015 </strong> <strong>Abstract:</strong> New strategies with potential applications can be developed from our existing ideas and perceptions simply looking at the things from different angles with open mind. In this talk I will be sharing some of such endeavors from our research group. It is a common and accepted understanding that an ionic molecular probe is unable to sense ions of similar charge characteristics due to the electrostatic repulsion disallowing any hand-shaking between the two interacting partners. However, with the experience from the society and realizing the beneficial role of a "BROKER" in certain fields, we have been successful to overcome this limitation. To the best of our knowledge this is the first example of this sort. Simply through modifying the environment by introducing some selected surfactants as "broker"s we have been able to detect and estimate Cu2+ by the cationic fluorophore, phenosafranin. Ratiometric absorbance of two bands of a pH sensitive probe has enabled us to detect and estimate the deadly toxic cyanide ion down to micromolar level of concentration by exploiting the basic chemistry of hydrolysis of cyanide salt that leads to an appreciable change in the solution pH. For improvement of the delivery of ionic drugs to the target region, the concept of electrostatic pushing has been exploited by us using model systems. An anionic probe (model of a drug) has been pushed deeper into the hydrophobic regions of a micelle as well as ctDNA by the electrostatic repulsion exerted by the anions of externally added salts. We have also developed a prospective strategy for the removal of excess drugs adsorbed on the cell membrane by exploiting the idea of competitive binding of a molecular probe between various environments. Using fluorophores as models of drugs and lipids as models of membrane, we have shown that the lipid bound probe can be extracted from the lipid bilayer into the aqueous medium by the simple use of cylodextrins. The strategy has further been shown to be applicable to the living cells. A simple and useful strategy has been developed for the specific synthesis of gold nanoparticles of desired dimension. Interestingly the instrument required for the size determination is spectrophotometer only. Thus, it is very much possible to engender imperative strategies simply by the logical extension of familiar notions.