Enhanced fluorescence effect from complex nanostructure decorated with the native oxide layer

Abstract

A complex nanostructure, consisting of silver nanoparticles (AgNPs) and mechanically polished nanostructure copper surface (MPNCS), was fabricated with physical polishing and spin coating method. The distance between the AgNPs and MPNCS was moderated with a native oxide layer. Experimental results show that the substrate enhancement efficiency, in terms of surface-enhanced fluorescence intensities of the target molecules (Rh6G), critically depends on the oxide layer thickness. Theoretical analysis shows that non-radiative energy transfer process and electromagnetically coupled effect between the AgNPs and MPNCS are important in the enhancement of fluorescence. As a result, careful control of the native oxide layer thickness formed from enhanced substrate fabrication is important for studying the mechanism and for expanding the potential applications of enhanced fluorescence.