Fluorescence properties of Ag nanoparticles in water

Ag nanoparticles in water phase have been synthesized employing the electro-exploding wire technique. A surface plasmon peak is observed at 400 nm, characteristic of the Ag nanoparticles. A fluorescence emission peak is recorded at 300 nm for excitation wavelengths in two different ranges 215–230 and 255–280 nm. The position of the fluorescence peak remains fixed, irrespective of the excitation wavelength employed. These are assigned to electronic transition from different higher excited states to d levels of the Ag nanoparticles. In concomitant with these, there are two resonant absorptions at 5.76 and 4.59 eV as evident from the fluorescence excitation spectra.