Studies On Application Of Glutathione Stablized Fluorescent Noble Metal Nanoclusters And Their Photo-reduction Synthesis

Due to their super-small size, great specific surface area, adjustable fluorescence emission wavelength, photostability and are biocompatible, noble metal nanoclusters posess have been reasearched by many science researchers and have been considerd as promising applications such as medical tratment, environment monitoring, and bioimaging. In this paper, glutathione stable fluorescent gold nanoclusters were synthesized and their analytical applications for heavy metal ions were studied. The use of this aggregation induced luminescence properties of gold nanoclusters, solved the problem of poor selectivity in the analysis of heavy metal ions using conmon Au nanocluster, and realized selective and sensitive detection of cadmium, copper ions. In addition, a new photoreduction method to the synthesis of fluorescent noble metal nanocluster was studied. Glutathione stablized gold-silver nanoparticles, glutathione stablized gold-silver nanoclusters were synthesized and their spectral properties, applicions for biological small molecule analysis were studied. The specific contents of the thesis are as follows:1. Glutathione stablized gold clusters was synthesized and mixed with cysteine. A non-fluorescent glutathione-gold-cysteine nanoclusters compound was formed, and the fluorescence was quenched. Such nanocluster has better AIE perporty and higher selectivity to metal ions, compaering with common glutathione gold clusters. In common heavy metal ions, only cadmium ions can induce the AIE of glutathione Au nanoclusters, that enabling a highly selective detection of cadmium ions in the range from 10μM to 200μM.2. A glutathione stablized gold clusters was synthesized aggregated by cadmium ion for AIE. Such fluorescence nanoclusters aggreagetion could interact with copper ions selectively, that qunenching the fluorescence of the nanoclusters. Compared with common glutathione-gold clusters, the fluorescence nanoclusters aggregates can be used to detection copper ions sensitivity and selectivity. Common interferces, such as mercury ions, can not affect the detction of copper ions. Thus, copper ions in the range of 0.1μM to 5μM was selectively and sensitively detected.3. Synthesized gold and silver alloy nanoparticles by photoreduction method using glutathione and sodium citrate as a stabilizer. The photoreduction synthesized gold and silver alloy nanoparticles have good pH stability and salt resistance. In addition, the nanoparticles can be aggregated by dopamine in pH of 12, resulting in changes in the absorption spectrum. According to the changes in the absorption spectra, a method for dopamine detection in range from 5μM to 160μM was establsehed.4. A red light emission fluorescent gold and silver alloy nanoclusters was synthesized by photoreduction method using glutathione and sodium citrate as a stabilizers, in the presence of lipoic acid. The ingredients, fluorescence spectroscopy, and quantum yields of the as-prepared nanoclusters were characterized, and the stablility of the nanoclusters was also studied.5. A human serum albumin stabilized gold nanoclusters probe was synthesized and used to interact with folic acid. Base on the fact that the fluorescece of gold nanoclusers at 620 nm can be quenched, while 450 nm can be enhanced by folic acid. A fluorescence ratio method for folic acid detection was established in concentration range from 1μM to 30μM. Compared to conventional fluorescence method, the fluorescence ratio method has better linearity and higher selectivity.