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The handle http://hdl.handle.net/1887/62864 holds various files of this Leiden University dissertation
Author: Zhang, Weichun
Title: Plasmonic enhancement of one-photon- and two-photon-excited single-molecule fluorescence by single gold nanorods
Date: 2018-06-28
Plasmonic Enhancement of One-Photon- and Two-Photon-Excited Single-Molecule Fluorescence by
Single Gold Nanorods
Proefschrift
ter verkrijging van
de graad van Doctor aan de Universiteit Leiden, op gezag van Rector Magnificus prof. mr. C.J.J.M. Stolker,
volgens besluit van het College voor Promoties te verdedigen op woensdag 27 juni 2018
klokke 16:15 uur
door
Weichun Zhang
geboren te Anhui, China in 1989
Promotor:
Prof. dr. M. A. G. J. Orrit Universiteit Leiden Copromotor:
Dr. M. Caldarola Universiteit Leiden
Promotiecommissie:
Prof. dr. E. R. Eliel Universiteit Leiden
Prof. dr. T. Schmidt Universiteit Leiden
Prof. dr. E. Bouwman Universiteit Leiden
Prof. dr. M. Lippitz Universität Bayreuth
Prof. dr. H. Zhang Universiteit van Amsterdam
Dr. M. J. A. de Dood Universiteit Leiden
Keywords: Gold nanorods, surface plasmon resonance, fluorescence, single molecules, electrochemistry, two-photon, quantum dots
Printed by: Gildeprint
Front & Back: Photograph by Yang Hong.
Copyright c 2018 by W. Zhang
Casimir PhD Series, Delft-Leiden 2018-20 ISBN 978-90-8593-349-6
An electronic version of this dissertation is available at http://openaccess.leidenuniv.nl/.
The present work is financially supported by the Netherlands Organization for Scientific Re- search (NWO). The author acknowledges a Ph.D. grant from the China Scholarship Council.
Contents
1 Introduction 1
1.1 Light absorption and emission . . . 2
1.1.1 Jablonski diagram . . . 2
1.1.2 One-photon-excited fluorescence. . . 3
1.1.3 Two-photon-excited fluorescence. . . 3
1.1.4 Hot-band absorption induced anti-Stokes luminescence. . . 4
1.2 Single-molecule fluorescence spectroscopy. . . 4
1.3 Plasmonic nanoantennas and fluorescence enhancement. . . 5
1.3.1 Localized surface plasmons. . . 5
1.3.2 Fluorescence enhancement . . . 6
1.3.3 Gold nanorods . . . 7
1.4 Outline of the thesis . . . 9
References. . . 11
2 Plasmonic enhancement of a near-infrared fluorophore using DNA transient binding 17 2.1 Introduction . . . 18
2.2 Materials and methods . . . 19
2.3 Results and discussion . . . 21
2.3.1 Binding sites on the nanorod surface . . . 21
2.3.2 Binding sites on the substrate. . . 25
2.3.3 Numerical simulations . . . 27
2.4 Conclusions and outlook . . . 28
2.5 Supporting information. . . 28
2.5.1 Sample preparation. . . 28
2.5.2 Correction of gold nanorod spectra. . . 31
2.5.3 Size of the confocal volume. . . 31
2.5.4 Saturation of IRDye800CW . . . 32
2.5.5 Numerical simulations of fluorescence enhancement . . . 32
2.5.6 Calculation of nanorod temperature increase . . . 35
References. . . 35
3 Gold nanorod-enhanced fluorescence enables single-molecule electrochem- istry of methylene blue 41 3.1 Introduction . . . 42
3.2 Results and discussion . . . 42
3.3 Conclusions . . . 46
3.4 Supporting information. . . 47
3.4.1 Experimental setup. . . 47 iii
Contents
3.4.2 Sample preparation. . . 48
3.4.3 Modeling the ensemble response to the potential . . . 50
3.4.4 Blinking time scales . . . 51
3.4.5 Histogram of single-molecule mid-point potentials . . . 52
3.4.6 Dependence of the electrochemical reaction on the laser intensity. . 52
3.4.7 Fluorescence enhancement analysis. . . 53
3.4.8 Scatter plots . . . 55
References. . . 56
4 Enhancement of hot-band absorption anti-Stokes luminescence of single molecules by individual gold nanorods 61 4.1 Introduction . . . 62
4.2 Materials and methods . . . 63
4.3 Results and discussion . . . 64
4.3.1 Optical characterization at room temperature . . . 64
4.3.2 Temperature-dependent optical characterization. . . 65
4.3.3 Femtosecond laser excitation . . . 67
4.3.4 Enhancing hot-band absorption using gold nanorods . . . 67
4.4 Conclusion. . . 69
4.5 Supporting information. . . 69
References. . . 75
5 Plasmonic enhancement of two-photon-excited luminescence of single quan- tum dots by individual gold nanorods 77 5.1 Introduction . . . 78
5.2 Materials and methods . . . 79
5.3 Results and discussion . . . 80
5.4 Conclusions . . . 88
5.5 Supporting information. . . 88
5.5.1 Two-photon fluorescence correlation spectroscopy . . . 88
5.5.2 Burst analysis: correlation between duration and intensity. . . 90
5.5.3 Blank experiments . . . 90
5.5.4 Quantum dot concentration dependence. . . 91
5.5.5 Enhancement time traces at different NaCl concentration . . . 91
5.5.6 One-photon luminescence decay of quantum dots. . . 93
5.5.7 Excitation saturation . . . 95
5.5.8 Enhancement factor simulations . . . 96
5.5.9 Quantum dot structure . . . 97
5.5.10 Effect of finite size of the quantum dot . . . 98
References. . . 98
6 Plasmonic enhancement of molecular two-photon-excited fluorescence by in- dividual gold nanorods 105 6.1 Introduction . . . 106
6.2 Experimental section. . . 106
6.3 Results and discussion . . . 107
6.4 Conclusion. . . 109 iv
Contents
6.5 Supporting information. . . 109 References. . . 113
7 Conclusions and outlook 115
References. . . 118
Samenvatting 121
Curriculum Vitæ 125
List of Publications 127
Acknowledgements 129
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