Design of a novel FRET based fluorescent chemosensor and their application for highly sensitive detection of nitroaromatics.

Abstract

We report the development of a Fluorescence Resonance Energy Transfer (FRET) based sensor system for highly sensitive detection of nitro-aromatic compounds. The sensor system is composed of a copolymer (poly(methyl methacrylate (MMA))-co-7-(4-trifluoromethyl)coumarin-N-methacrylamide (TCMA)) (CP)1 bearing coumarin derivative in the side chain as donor and curcumin (dye) as an acceptor. Primarily, the fluorescence of the above mentioned copolymer is quenched by non-radiative energy transfer to curcumin which occurs when the two molecules are within FRET distance scale. The efficiency of this FRET process was calculated. A noticeable decrease in the FRET signal is observed as nitroaromatics viz. 2,4-dinitrotoluene (DNT) and 2,4,6-trinitrotoluene (TNT) is gradually introduced into the sensor system. Fluorescence lifetime is measured to validate the efficacy of the energy transfer process in CP-curcumin sensor system. The mechanistic details of molecular interactions between CP and curcumin system are established by infrared spectroscopy and UV–vis absorption spectroscopy.