Strong plasmonic fluorescence enhancement of individual plant light-harvesting complexes

Abstract

Correspondence Author -Tjaart P. J. Krüger, tjaart.kruger@up.ac.za.Abstract-Plasmonic coupling of metallic nanoparticles and adjacent pigments can dramatically increase the brightness of the pigments due to the enhanced local electric field. Here, we demonstrate that the fluorescence brightness of a single plant light-harvesting complex (LHCII) can be significantly enhanced when coupled to single gold nanorods (AuNRs). The AuNRs utilized in this study were prepared via chemical reactions, and the hybrid system was constructed using a simple and economical spin-assisted layer-by-layer technique.Enhancement of fluorescence brightness of up to 240-fold was observed, accompanied by a 109-fold decrease in the average (amplitude-weighted) fluorescence lifetime from approximately 3.5 ns down to 32 ps, corresponding to an excitation enhancement of 63-fold and emission enhancement of up to 3.8-fold. This large enhancement is due to the strong spectral overlap of the longitudinal localized surface plasmon resonance of the utilized AuNRs and the absorption or emission bands of LHCII. This study provides an inexpensive strategy to explore the fluorescence dynamics of weakly emitting photosynthetic light-harvesting complexes at the single molecule level.

Ultrasensitive Detection of Exosome Using Biofunctionalized Gold Nanorods on a Silver-Island Film

“…Therefore, the large fluorescence enhancement in the current work may be attributed to the spectral correlation between resonance in the metal nanostructure and spectral properties of the fluorophore. This association improves the QY, radiation decay rate, and fluorophore lifespan, which are all related to fluorescence enhancement. − The AF647 molecule shows an absorption peak at 650 nm (Figure S2a). The wavelength of the excitation laser, 633 nm, is on the shoulder of the AF647 molecule absorption peak.…”

Photon Correlation Spectroscopy as a Witness for Quantum Coherence

“…In this paper, we introduce photon correlation spectroscopy as a possible tool to measure coherent dynamics and the presence of steady state coherence between excitons in single molecule spectroscopy. Our proposal relies on measure-ments of photon correlations of the light emitted by single molecular aggregates [33][34][35][36][37][38] in natural, non-equilibrium situations. In particular, we show how the presence of steadystate coherence can be detected in two-photon coincidence measurements by varying the detection polarization.…”

Plasmonic protein electricity generator

“…Previous studies of the interactions of gold or silver NPs with photosynthetic proteins have focussed in the main on the photophysical consequences, including enhanced absorption and energy transfer. [80][81][82][83][84][85][86][87][88][89][90][91][92] A smaller number of studies have reported the impact of plasmonic interactions on photocurrents from photosynthetic materials on electrodes or in cells. Enhancements have been seen after placing Photosystem I complexes on a silver island film 93 and decorating thylakoid membranes with gold nanorods.…”