Plasmonic nanoprobes for stimulated emission depletion microscopy

TL;DR

This paper introduces plasmonic gold nanorods as probes to enhance stimulated emission depletion microscopy, achieving significantly improved resolution and enabling cellular imaging with plasmon-assisted STED.

Contribution

It presents the first use of plasmonic nanoparticles in STED microscopy, demonstrating a ~2000-fold reduction in probe volume and improved resolution in cellular imaging.

Findings

Enhanced resolution in STED microscopy using gold nanorods

Achieved ~2000-fold reduction in probe volume

First demonstration of plasmon-assisted cellular imaging

Abstract

Plasmonic nanoparticles influence the absorption and emission processes of nearby emitters due to local enhancements of the illuminating radiation and the photonic density of states. Here, we use the plasmon resonance of metal nanoparticles in order to enhance the stimulated depletion of excited molecules for super-resolved microscopy. We demonstrate stimulated emission depletion (STED) microscopy with gold nanorods with a long axis of only 26 nm and a width of 8 nm that provide an enhancement of the resolution compared to fluorescent-only probes without plasmonic components irradiated with the same depletion power. These novel nanoparticle-assisted STED probes represent a ~2x10^3 reduction in probe volume compared to previously used nanoparticles and we demonstrate their application to the first plasmon-assisted STED cellular imaging. We also discuss their current limitations.