Nanoparticle-assisted STED nanoscopy with gold nanospheres

TL;DR

This paper introduces a novel nanoparticle-assisted STED microscopy technique using gold nanospheres, achieving higher resolution, lower intensity requirements, and reduced photobleaching, which enhances bio-imaging capabilities.

Contribution

It presents a new STED approach with gold nanospheres that improves resolution and photostability over traditional dye-based methods.

Findings

Achieved 2.5-fold resolution enhancement beyond confocal microscopy.

Reduced required laser intensity by approximately 50%.

Demonstrated a threefold decrease in photobleaching rate.

Abstract

We demonstrate stimulated emission depletion (STED) microscopy with 20 nm gold nanospheres coated by fluorescent silica. Compared with previous demonstrations of STED with a hybrid plasmonic fluorescent label, the current implementation offers a substantially smaller label and a better resolution improvement of up to 2.5-fold beyond the diffraction limit of confocal microscopy. This is achieved at approximately 2 times lower intensity than conventional STED based on dyes alone, and in an aqueous environment, demonstrating the relevance to bio-imaging. Finally, we also show, for the first time in this context, a 3-fold reduction in the rate of photobleaching compared to standard dye-based STED, thus, enabling brighter images.