Fluorescent Dyads as Sensors for Particular Cations and Anions

Abstract

Optical sensors based on NBD, thiazolidine, FRET/TBET dyads operating via different mechanism have been synthesized as they have auspicious future. NBD based dyads through Schiff bases have been synthesized as colorimetric and fluorescent chemosensors. These dyads are used to quantify Cu2+, Ni2+, Al3+, Hg2+, CN- ions in organic and semi-aqueous solvents depending upon the dyad. Then, thiazolidine based molecules have been synthesized as novel sensors to sense Cu2+, F-, CN-, H2PO4-, HSO4-, Hg2+, Al3+ etc. in different solvents. These molecules further elaborated as logic devices. In the last, rhodaminenaphthalimide dyad operating via FRET and phenanthroimidazole-anthraquinone dyad operating via TBET has been synthesized and used for the investigations of photophysical properties in the presence of various ions. These designed chemosensors in the present work used for the ion quantification, the ability to operate in water, having sufficient lifetime and sensitivity at wide pH range, recognize the various analytes in the aerobic and aqueous medium. Moreover, the design and synthesis of inexpensive and disposable sensor such as sensor strips have been highly desired. NBD and thiazolidine based sensors display significant color changes in the presence of particular ion solution, therefore, used as sensor strips. These optical sensors represented by three models; show high selectivity for a particular ion in the presence of other ions of similar nature.