Exploring the Fluorescence Quenching of Sodium Dodecyl Sulfate Doped Polyaniline by Energetic Nitrocompounds

The fluorescence quenching studies using conducting polymers (CPs) have greatly contributed in the trace detection of high energy materials (HEMs) with nitro functional groups. Polyaniline doped with the anion surfactant sodium dodecyl sulfate (SDS) acts as a fluorophore and is used in fluorescence quenching studies to detect HEMs at trace levels. A mechanistic approach to understanding electron transfer during the interaction of fluorophore with HEMs were studied by using spectroscopic and electrochemical techniques. The presence of conjugation in conducting polymer shows a molecular wire effect during fluorescence quenching by trace level of HEMs by quenching several emissions in polymer chains. The Stern-Volmer(S-V) and limit of detection(LOD) plots give quenching mechanism and the efficiency of quenching. These values indicate that TNT had good sensitivity compared to other HEMs such as RDX, PETN, CL-20 and CRCC. The FTIR and Raman studies were used to understand the interaction between nitro groups of HEMs with the benzenoid, polaronic and semi-quinoid units of doped polyaniline. The cyclic voltammetry studies revealed shift in potential and current during the interaction of the fluorophore with HEMs, and these results were combined with fluorescence studies for better understanding of the possible mechanism of quenching. A morphologically modified functionalized polyaniline (SDS-PANI) used for fluorescence quenching studies for sensing of energetic nitrocompounds as analytes in trace levels with good sensitivity following photo-induced electron transfer mechanism. The benzonoid and poloranic group interaction between SDS-PANI and analyte is studied by FTIR and Raman spectra for understanding mechanism of interaction. Further fluorescence studies are collaborated with electrochemical approach employing cyclic voltameter.image