Preparation Of Fluorescent Copper Nanoclusters And Their Application In Analysis And Detection

In this work,three kinds of nucleosides were used as templates,ascorbic acid as reducing agent and sodium citrate as pH regulator to synthesize fluorescent copper nanoclusters（CuNCs）in a simple one-pot method.An optical sensor was constructed using CuNCs as fluorescent probes for qualitative and quantitative analysis of Cu²⁺,Cr（VI）and nitrofurantoin in environmental water,and hemin in animal blood.Furthermore,the recognition of nucleosides system has been also established using fluorescent CuNCs combined with chemometrics.The proposal proposed in this work is convenient and rapid,low in cost,easy to operate,response quickly,and high in sensitivity and selectivity,it can be applied in real samples.The main content of the article is summarized as follows:The first chapter:We described the related properties of metal nanomaterials,briefly.Sch as the research background,the preparation methods that have been developed and the application research of their special physical and chemical properties in biology and chemistry.On the other hand,we also overview of the testing objects involved in this work was presented,and the innovative points of the research were proposed.The application prospects of fluorescent copper nanoclusters in other fields were prospected.The second chapter:Using three kinds of nucleosides as templates,ascorbic acid as reducing agent,sodium citrate as p H regulator and using a simple one-pot method to synthesis of fluorescent CuNCs.The physical and chemical properties were characterized by X-ray diffraction（XPS）,transmission electron microscopy（TEM）,infrared spectroscopy（FTIR）,UV-Vis and fluorescence spectroscopy（FL）.And the recognition of nucleosides system has been also established using fluorescent CuNCs combined with chemometrics,Analyzed and identified the nucleoside.The third chapter:In this section,we developed a strategy to detected Cu²⁺and hemin by using cytidine-protected CuNCs as fluorescence probes,respectively,and obtained a good linearity and limit of detection.In addition,it has also been demonstrated by using various analytical characterization techniques that a fluorescent"turn on"sensor were based on the formation of fluorescent CuNCs to detection of Cu²⁺and the“turn off”sensor were established based on the inner filter effect between hemin and CuNCs.Finally,the proposed experimental scheme was applied to the detection of Cu²⁺and hemin in real samples.The fourth chapter:Based on the fact that the fluorescence of CuNCs could been quenched by Cr（VI）,we proposed a fluorescent probes as an optical sensor for detecting Cr（VI）,based on the CuNCs synthesized in the previous chapter.A good linear range and detection limit were obtained,and the mechanism of fluorescence quenching was studied.The experimental results show that the sensor has good selectivity for Cr（VI）,which could be applied to detection of Cr（VI）in the environmental system.The fifth chapter:In this section,we have constructed a novel strategy for label-free analysis method.Nitrofurantoin could cause a rapid decrease in the fluorescence intensity of adenosine-protected CuNCs,thus it could be used to highly sensitive and selective detection of nitrofurantoin（NFT）.And it was explored that the mechanism of fluorescence quenching may be attributed to the inner filter effect between nitrofurantoin and CuNCs.The sensor was finally successfully applied to the detection of nitrofurantoin in lake water samples.The main innovations of this studies as follows:（1）Synthesis of small-size fluorescent CuNCs and used its construction of optical sensors for the detection of several substances in the environment and biological samples,showing good selectivity and sensitivity;（2）Combined with chemometrics to construct three kinds of nucleoside pattern recognition system,the three kinds of nucleosides were analyzed and identified,and rational interpretation of the experimental mechanism of the fluorescence sensor detection process.