Fluorescence quenching of osthole by silver nanoparticles

The luminescence properties of osthole in the presence of spherical silver nanoparticles (AgNPs) with sizes ranging from 5 to 25 nm were investigated by means of fluorescence and absorption spectroscopic experiments, as well as time-resolved fluorescence experiments. Quenching of the fluorescence of osthole has been found to increase with a reduction in the sizes of the silver nanoparticles. Using the Gersten-Nitzan model, the theoretical and experimental results were compared, and the results are in good unity. Stern-Volmer quenching constants have also been calculated. Both dynamic quenching and static quenching mechanisms exist between osthole molecules and silver nanoparticles. (C) 2013 Optical Society of America