Na-Ag Ion-Exchanged Glass Substrates for Plasmon-Enhanced Fluorescence Imaging of Neutrophils

Here, we study the fluorescence response of neutrophils stained with the wheat germ agglutinin Alexa Fluor 594 dye when the cells are placed on plasmonic nanoparticle substrates. Specifically, we focused on gold and silver nanoparticles with particle sizes ranging from 12 to 250 nm. It was demonstrated that the intensity of fluorescence can be increased by more than 10 times when using substrates with silver nanoparticles formed by Na⁺-Ag⁺ ion exchange in glass. The fluorescence enhancement depends significantly on both the size and surface density of the silver nanoparticles and the membrane staining procedure.