This thesis is a collection of experimental attempts to enhance photoluminescence of fluorescent molecules and quantum dots with single gold nanorods (GNRs) and relevant applications. Special... Show moreThis thesis is a collection of experimental attempts to enhance photoluminescence of fluorescent molecules and quantum dots with single gold nanorods (GNRs) and relevant applications. Special attention is focused on the interactions between single emitters and GNRs. The idea is to increase the emission of weak emitters by the excellent optical properties of GNRs so that weak light emitters will then be bright enough to be detected and studied individually. We can thus generalize single-molecule fluorescence spectroscopy to weakly emitting species which are currently undetectable by conventional single-molecule spectroscopy. The research is important for extending the scope of single-molecule spectroscopy, which is a powerful technique for understanding the dynamic behaviors at the nanometer scale in biological systems and other materials. Show less
Single-molecule fluorescence was invented in the 1990s and has quickly developed into an indispensable technique in the biomedical sciences and condensed-matter research. It has revolutionized... Show moreSingle-molecule fluorescence was invented in the 1990s and has quickly developed into an indispensable technique in the biomedical sciences and condensed-matter research. It has revolutionized the fields of molecular biology, imaging (super-resolution), and catalysis, to name a few. In this thesis, we will apply fluorescence enhancement by single gold nanorods to extend single-molecule studies to chromophores with low fluorescence quantum yields and to high concentrations of probe molecules. Following single-molecule trajectories, we will explore variations in the electron-transfer rates of the metalloprotein azurin both from molecule to molecule and for the same molecule as a function of time. Evidence for conformational substates will be discussed based on dynamic heterogeneity. Show less
