Spatial imaging of modifications to fluorescence lifetime and intensity by individual Ag nanoparticles

TL;DR

This study uses fluorescence lifetime imaging microscopy to spatially map how silver nanoparticles modify the fluorescence lifetime and intensity of nearby dye molecules, revealing significant local enhancements due to surface plasmon effects.

Contribution

It demonstrates the ability to visualize and quantify localized changes in fluorescence properties caused by silver nanoparticles using FLIM.

Findings

Localized increase in fluorescence decay rate near nanoparticles

Enhanced fluorescence emission intensity in nanoparticle vicinity

High-resolution spatial maps of lifetime components

Abstract

Highly ordered periodic arrays of silver nanoparticles have been fabricated which exhibit surface plasmon resonances in the visible spectrum. We demonstrate the ability of these structures to alter the fluorescence properties of vicinal dye molecules by providing an additional radiative decay channel. Using fluorescence lifetime imaging microscopy (FLIM), we have created high resolution spatial maps of the molecular lifetime components; these show an order of magnitude increase in decay rate from a localized volume around the nanoparticles, resulting in a commensurate enhancement in the fluorescence emission intensity.