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 a gold nanorod (AuNR). 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.
| Original language | English |
|---|---|
| Pages (from-to) | 15139-15146 |
| Number of pages | 8 |
| Journal | Nanoscale |
| Volume | 11 |
| Issue number | 32 |
| Early online date | 29 Jul 2019 |
| DOIs | |
| Publication status | Published - 28 Aug 2019 |
Funding
We thank Erica Belgio for providing the LHCII sample. We also acknowledge funding from the National Research Foundation (NRF), South Africa grant no. 102431 (F. K.), grant no. 8990, 94107, 112085 and 109302 (T. P. J. K.). T. P. J. K. was further supported by the Photonics Initiative of South Africa, Rental Pool Programme of the National Laser Centre, South Africa, Department of Science and Technology and the University of Pretoria through the Research Development Programme, Strategic Research Funding and the Institutional Research Theme on Energy. M. D. acknowledges funding from the NRF Nanotechnology Flagship Program grant no. 88021. J. L. B. was supported by the Vrije Universiteit Amsterdam– NRF South Africa Desmond Tutu Programme. B. v. H was supported by the Department of Science and Technology–NRF grant no. 115463. R. v. G. gratefully acknowledges his “Academy Professor” grant from the Netherlands Royal Academy of Arts and Sciences (KNAW).
| Funders | Funder number |
|---|---|
| Institutional Research Theme on Energy | |
| NRF Nanotechnology Flagship Program | 88021 |
| Netherlands Royal Academy of Arts and Sciences | |
| Rental Pool Programme of the National Laser Centre | |
| National Research Foundation | 8990, 102431, 94107, 109302, 112085 |
| University of Pretoria | |
| Department of Science and Technology, Ministry of Science and Technology, India | |
| Koninklijke Nederlandse Akademie van Wetenschappen | |
| Vrije Universiteit Amsterdam | 115463 |