Surface enhanced fluorescence of Rh6G with gold nanohole arrays.

Five gold nanohole arrays with distinct aperture size were fabricated by magnetron sputtering technique. Fluorescence enhancements of Rh6G fluorophore in the close vicinity of gold nanohole arrays were observed. Up to 40 times increase of fluorescence intensity was obtained from gold nanohole arrays as compared with a smooth gold surface control sample. A double-peak curve was presented in the excitation spectrum of enhanced fluorescence emission when the excitation wavelength was scanning from 300 nm to 550 nm. It was found that smaller aperture size and proper excitation wavelength matching with the surface plasmon resonances condition were favorable for a better fluorescence enhancement.