Excited State Interaction of Laser Dyes and Silver Nanoparticles in Different Media

Quenching the fluorescence of the dyes 3-(4’-dimethylaminophenyl)-1-(1H-pyrrol-2-yl)prop-2-en-1-one (DMAPrP), 3- (4’-dimethylaminophenyl)-1-(2-furanyl)prop-2-en-1-one (DMAFP) and 3-(4’-dimethylaminophenyl)-1-(2-thienyl)prop- 2-en-1-one (DMATP) has been investigated in the presence of silver cation and silver nanoparticles in different media. The results of the quenching experiments were analyzed using Stern-Volmer equation. Quenching the fluorescence of the dyes decreased with increasing medium viscosity. The Stern-Volmer constant (KSV) values in the absence and presence of ethylene glycol show that the quenching efficiencies decrease as the medium viscosity increases indicating that the quenching process is a diffusion-controlled process, and this is consistent with a dynamic-type quenching.