Fluorescence Enhancement by Metal‐Core/Silica‐Shell Nanoparticles

Abstract

Fluorescent nanoparticles have been synthesized with a metal core, silica-spacer shell, and a dye-labeled silica shell. Cascade-yellow-labeled, silver-core and carboxyfluorescein-labeled, gold-core nanoparticles with dye–metal distances of 24–25 nm exhibit fluorescence enhancement factors as high as 12.5 and 6.8, respectively. Cascade-yellow-labeled, gold-core particles with a dye–metal distance of ∼15 nm show significant fluorescence quenching.