We have fabricated well-defined nanostructures such as SiO 2-coated Ag nanoparticles (NPs) connected with quantum dots (QDs) (Ag/SiO2-QDs) so as to control the fluorescence enhancement induced by localized surface plasmon resonance. Namely, the distance between Ag NP and QD should be noted as a controllable model to investigate the fluorescence enhancement effect. Actually, highly monodispersed Ag NP as a core was first coated with five thicknesses of SiO2 as a shell, and then QDs were specifically adsorbed onto the surface of the amino-functionalized SiO 2-coated Ag NPs. As a result, the fluorescence intensity increased with the shell thickness as a result of excitation enhancement. On the other hand, the fluorescence intensity decreased when the shell thickness became thinner because of the induced quenching. Therefore, the distance between Ag NPs and QDs should be optimized to control and enhance the fluorescence intensity.
ASJC Scopus subject areas