The Application Of Fluorescent Gold Nanoclusters In Bioimaging And Biological Detection

In modern society, malignant tumor has become one of the major diseases that threaten human health, how to achieve effective diagnosis and treatment of cancer in the clinical has been the focus of bio-medical research. Tumor fluorescence imaging is an important means to achieve early diagnosis and real-time monitoring of cancer. In recent years, an increasing number of researchers have utilized nanomaterials to mark tumor cells specifically due to their excellent luminescent properties such as fluorescent nanocomposites, upconverting luminescent nanoparticles, precious metal nanoclusters and fluorescent quantum dots and developed highly sensitive optical imaging in cancer cells and small animal level. Fluorescent nanomaterials with good bio-compatibility and high signal to noise ratio have attracted more and more attention.Fluorescent gold nanoclusters have good water-solubility and high bio-compatibility which can be used as fluorescent probe because of their good bio-marking function. In this thesis work, we synthesized Au-BSA nanoclusters and made use of the nanomaterials to incubate with tumor cells in vitro such as MCF-7, HeLa and L02 cell lines and analyzed by laser scanning confocal imaging technique. In addition, we also characterized the targeting marker function of Au-BSA nanoclusters for in vivo tumor models. The results show that through a simple step hydrothermal synthesis method, using bovine serum albumin as a template, we have successfully obtained good bio-compatibility and stability of fluorescent Au-BSA nanoclusters. Our results suggest that Au-BSA nanoclusters have good fluorescent marking effect on MCF-7 and HeLa but not on L02 cell lines. Meanwhile, we further established xenograft tumor model of breast and cervical carcinoma. Subcutaneous injection of Au-BSA nanoclusters on xenograft tumors allowed the clear observation of bright fluorescence on the tumor site in a short time was observed by in vivo fluorescence.In addition, we also explored Au-BSA nanoclusters in biological detection application. It was found that mercury ions strongly interacted with the Au-BSA nanoclusters which could result in significant fluorescence quenching. According to this quenching effect, a Au-BSA nanoclusters detection and analysis platform for mercury ion was developed with selectivity, sensitivity and applicability in real sample analysis experiments.