Sensitive detection of nitro aromatic explosives using novel polythiophene nanoparticles

Fluorescent polythiophene nanoparticles were fabricated by surfactant assisted mini emulsion technique. The size distribution of the synthesized nanoparticles was characterized using dynamic light scattering (DLS) and scanning electron microscopy (SEM). The synthesized nanoparticles were also characterized using UV-Vis and fluorescence spectroscopy. Strong two-photon induced fluorescence was observed from these nanoparticles using 800 nm pulses from a femto second laser. The fluorescence response of these nanoparticles to nitro-aromatic explosives 2,4-dinitrotoluene and 2,4,6-trinitrotoluene in solution was investigated at different concentrations of the analytes. Strong fluorescence quenching was observed using both one photon and two-photon excitation source. The Stern Volmer constant is also higher.