Refractive Index Dependence of Fluorescence Enhancement in a Nanostructured Plasmonic Grating

Plasmonic gratings are attracting huge interest in the context of realizing sensors based on surface-enhanced fluorescence. The grating features control the plasmonic modes and consequently have a strong effect on the fluorescence response. Within this framework, we focused on the use of a buffer solution flowing across the grating active surface to mimic a real measurement. The refractive index of the surrounding medium is therefore altered, with a consequent modification of the resonance conditions. The result is a shift in the spectral features of the fluorescence emission accompanied by a reshaping of the fluorescence emission in terms of spectral weight and direction.

Automated summary

In the context of surface-enhanced fluorescence sensors, plasmonic gratings are gaining significant attention. The features of the grating can control plasmonic modes, thereby strongly affecting the fluorescence response. This study focuses on using a buffer solution flowing across the active surface of the grating to mimic real measurements. By altering the refractive index of the surrounding medium, the resonance conditions are modified, resulting in a shift in the spectral features and a reshaping of the fluorescence emission in terms of spectral weight and direction.