Synthesis Of Fluorescent Gold Nanoclusters And Applications In Analytical Chemistry

In recent years, with ultra small size, fluorescent gold nanoclusters (AuNCs) consisting of several or dozens of metal atom have been developed as a novel fluorescence nanomaterial. Because of their good biocompatibility, high fluorescence quantum yield (QY), simple preparation and other advantages, AuNCs have become the hot spot of research and application in the fields of analysis science and life science. At the same time, owning to their unique electronic structure and special physical and chemical properties, AuNCs are widely applied in the field of biolabeling, biochemical sensing, single-molecule imaging and optical imaging studies, which indicates AuNCs have a wide prospect in more applications. Gold nanoclusters can be prepared based on proteins or mercaptans and other organic molecules as templates to synthesize molecular aggregates with fluorescence characteristics. Therefore, on the basis of related literature review, we try to prepare fluorescent gold nanoclusters employing the templates of eggwhite (EW), bovine serum albumin (BSA) and L-histidine (His) respectively in this paper. The contents are as follows:(1) Fluorescent gold nanoclusters were prepared employing eggwhite as the template. The synthetic route is simple, easy to operate, green, economic and with high fluorescence yield. Employing the prepared EW-AuNCs as fluorescence probe, a novel method for detecting Hg2+was established based on the fluorescence quenching. Additionally, according to inhibiting fluorescence quenching effect, due to the binding interaction between Hg2+and glutathione (GSH), a new signal on sensor was developed to detect GSH.(2) Our research shows that the presence of Cu2+would induce the fluorescence quenching of prepared BSA-AuNCs due to the interaction of Cu2+and-SH in the BSA. However, with the addition of cysteine (Cys), the fluorescence intensity was recovered with the increasing content of Cys. According to this special phenomenon, a new fluorescence sensor of cysteine was designed. The sensor has a wide linear range (0.5-90μM), high sensitivity (LOD0.15μM) and good selectivity. At the same time, the reaction mechanism of the method was also discussed. The systemic study promotes the development of BSA-AuNCs in the analysis science and biological field.(3) Gold nanoclusters with blue fluorescence were synthesized based on L-histidine (His) template. A novel and highly sensitive sensor was developed for the determination of Co2+, according to the phenomenon that the fluorescence intensity was obviously reduced with the adding of Co2+to the prepared His-AuNCs solution. The sensor has a wide linear range (0.5-50μM), high sensitivity (LOD50nM) and good selectivity. This research would provide very important value in promoting the application of fluorescent gold nanoclusters as nanoprobe in the analysis and biological field.