Multiple scattering-assisted fluorescence amplification: towards biological applications

TL;DR

This paper demonstrates that adding nanoparticles to fluorescein solutions can significantly amplify fluorescence signals with potential biocompatibility, offering a new approach for biological imaging and sensing.

Contribution

It introduces a novel method of fluorescence amplification using nanoparticles, detailing experimental conditions and demonstrating substantial gain factors suitable for biological applications.

Findings

Achieved fluorescence gain factors up to 40

Reduced spectral linewidth of fluorescence signals

Observed pump-energy and nanoparticle concentration effects on pulse duration

Abstract

Stimulated amplification of fluorescence signals is obtained under conditions which approach biocompatibility by adding NanoParticles (NPs) to an aqueous solution of fluorescein. The conditions for the stability of the suspension and optimum dye concentration are detailed, together with considerations on photobleaching and phototoxicity. A dedicated experimental setup, coupled to a specified measurement protocol, prove that it is possible to obtain gain factors up to 40, with a considerable reduction in spectral fluorescence linewidth. A pump-energy- and NP-concentration dependence of the fluorescence pulse duration is interpreted as further proof of stimulated amplification. Perspectives and possible biological applications are discussed.