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 400nm, characteristic of the Ag nanoparticles. A fluorescence emission peak is recorded at 300nm for excitation wavelengths in two different ranges 215-230 and 255-280nm. 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 4.59eV as evident from the fluorescence excitation spectra.