Development of new fluorescent chemosensors for various analytes and their evaluation as molecular logic gates (PhD)

Abstract

In recent years, the detection and quantification of biologically and environmentally important ions and small molecules have emerged as significant goals in the field of supramolecular chemistry. Among the various chemosensors used for these purposes, fluorescent chemosensors have attracted particular attention because of their high sensitivity and potential for in vitro and in vivo analyses. A fluorescent chemosensor is a molecular system in which the physicochemical properties of a fluorophore moiety vary upon interaction with a chemical species so that a change in fluorescence is produced. Fluorescent chemosensors have several advantages over other optical sensors because of their versatility, high selectivity/sensitivity, reliability & reproducibility, low detection limit (LOD), low cost, non-invasive nature and potential for real-time analyses. Fluorescent chemosensors are often explored towards other applications as well, such as the construction of molecular logic gates. This is because, the chemosensors exhibit large differences in their photophysical properties in “OFF” and “ON” states, which can therefore be treated as “0” and “1” states, enabling their applications in molecular logic operations. In the present thesis, a series of fluorescent chemosensors based on different fluorescent platforms have been developed towards the detection of various small molecules, cations and anions. The photophysical and binding properties of these new fluorescent chemosensors have been explored in detail and possible mechanisms of their binding interactions with analytes have been established through spectroscopic studies. Some of the fluorescent chemosensors have been explored towards their bio-imaging and molecular logic gates applications as well.