Resolution and enhancement in nanoantenna-based fluorescence microscopy

TL;DR

This paper investigates how gold nanoparticle nanoantennas can enhance fluorescence microscopy, achieving resolutions below 20 nm and up to 30-fold fluorescence enhancement through experimental and theoretical analysis.

Contribution

It provides new insights into the relationship between nanoparticle size, fluorescence enhancement, and spatial resolution in nanoantenna-based microscopy.

Findings

Resolutions better than 20 nm achieved experimentally.

Fluorescence enhancement up to 30 times demonstrated.

Finite-difference time-domain calculations explain interface effects.

Abstract

Single gold nanoparticles can act as nanoantennas for enhancing the fluorescence of emitters in their near-fields. Here we present experimental and theoretical studies of scanning antenna-based fluorescence microscopy as a function of the diameter of the gold nanoparticle. We examine the interplay between fluorescence enhancement and spatial resolution and discuss the requirements for deciphering single molecules in a dense sample. Resolutions better than 20 nm and fluorescence enhancement up to 30 times are demonstrated experimentally. By accounting for the tip shaft and the sample interface in finite-difference time-domain calculations, we explain why the measured fluorescence enhancements are higher in the presence of an interface than the values predicted for a homogeneous environment.