Fluorescence enhancement of ruthenium complex on silver using different chain length carboxylic acid terminated thiols: Distance and metal concentration study

The fluorescence enhancement of ruthenium complex (Ru(bpy) ₃ ²⁺) was studied on silver surface deposited by simple Tollens mirror reaction. The plasmon effects on spacer distance, silver concentration, and deposition methods were examined. Silver nanoparticles prepared were coated with different chain length carboxylic acid-terminated thiols as spacers. This leads to development of distance between Ag and Ru dye being varied from 4 to 23 A. Effect of different silver deposition methods on the emission spectra was also studied using metal evaporator deposition method. The results show that Ag concentration, Ag film roughness, and specific distance between metal and dye should be tuned for a maximum increase in fluorescence.