Abstract:

The effects of silver nanoparticles on the fluorescence properties of a [Ru(bpy)3]2+ complex bound to the surface of silver nanoparticles and an electrolyte effect were studied in this paper. Chain-like nanoparticle aggregates were formed due to bridging of [Ru(bpy)3]2+ on the surface of the silver nanoparticles. The fluorescence intensity of the [Ru(bpy)3]2+ complex was quenched and the larger size silver nanoparticles were found to be more efficient quenchers. The electrolyte ions allow the formation of large silver nanoparticles and aggregates in solution. The effect of electrolytes on the aggregates of silver nanoparticles decreases in the order: CaCl2>MgCl2>Ca(NO3)2>KCl>KNO3. As the electrolyte content increases, the fluorescence intensity initially decreases and then increases until it reaches a constant value. These results indicate that the electrolytes decrease the quenching effect. The effect of electrolytes on the fluorescence intensity of the [Ru(bpy)3]2+-Ag solution decreases as follows: Ca(NO3)2>CaCl2>MgCl2>KCl>KNO3. The effects of these electrolytes on the microstructure and fluorescence properties of the [Ru(bpy)3]2+ solution containing silver nanoparticles are discussed in terms of the interaction among the electrolytes and the energy transfer is investigated by transmission electron microscopy, UV-visible spectroscopy, and spectrofluorophotometry.

Key words: Silver nanoparticle, [Ru(bpy)3]2+, Localized surface plasmons resonance, Local field enhancement, Enhanced fluorescence, Quenched fluorescence, Electrolyte