The Preparation Of Inorganic Fluorescent Nanoprobes And Their Application In The Field Of Biochemical Detection

As keeping a watchful eye on fitness, food security, and the environmental protection, it’s necessary to develop rapid, timely, effective and simple detection technology. Compared with the organic fluorescent materials, the fluorescent inorganic nanomaterials demonstrate many advantages such as high chemical stability, low background interference, high photoluminescence quantum yield and long fluorescence lifetime. These advantages can make fluorescent inorganic nanomaterials to meet the requirements of the development of new detection technology. Hence, they can be applied in bioanalytical detection, in vivo imaging, and so on. In the current work, we prepared two kinds of inorganic fluorescent nanomaterials including upconversion photoluminescence NaYF4 nanoparticles and fluorescent gold nanoclusters. Then, these fluorescent nanomaterials were successfully utilized for the detection of hydrogen peroxide (H2O2), glucose, and Eschehchia Coli (E. Coli). The main progresses are as follows:1. The rapid, sensitive and selective detection of hydrogen peroxide and glucose has important theoretical research value in clinical and biochemical analysis. We developed a green upconversion photoluminescence system for the highly sensitive and selective detection of H2O2 and glucose in human sera by utilizing the excellent optical properties of NaYF4:Yb3+/Er3+ upconversion nanoparticles (UCNPs). At first, we prepared the oleic acid (OA) coated NaYF4 nanoparticles which were co-doped with Yb3+(15 mol%) and Er3+(5 mol%). Then we modified the hydrophobic upconversion nanoparticles (UCNPs) with polymer. Based on the special reaction among horse radish peroxidase (HRP),3,3’,5,5’-tetramethylbenzidine (TMB) and H2O2, we tested the amount of H2O2 and glucose with upconversion photoluminescence (UCPL) system.2. The rapid and sensitive detection of bacteria for public health and food safety is highly desirable. We built a new method for the synthesis of red fluorescence gold nanoclusters (AuNCs) which were applied in testing Escherichia coli (E. coli). Firstly, we set up a facile one-pot strategy based on microwave synthesis method for lysozyme functionalized fluorescence gold nanoclusters (AuNCs) using lysozyme as template. We optimized the preparation conditions such as the reaction temperature, time and ect. The lysozymes coated on the AuNCs surface and retained their specific recognition ability for bacteria such as E. coli. Then, based on such ability, we utilized AuNCs as a biological probe to realize the quantitative detection of E. coli.