Preparation Of Gold-based Bimetallic Gold Nanoclusters And Its Application In Analysis And Detection

Gold nanoclusters?AuNCs?usually have large Stoke frequency shift,low toxicity and good biocompatibility,so they are the ideal fluorescent materials with excellent performance.Metal doping is a simple and effective method to improve the fluorescence performance of AuNCs,and research in this field has also attracted the attention of many researchers.In this work,gold-based bimetallic nanoclusters with high fluorescence properties have been prepared by a simple and green method.After exploring the fluorescence enhancement mechanism of clusters,the fluorescent probes were constructed based on the fluorescence response of NCs to the target substance.This article first briefly introduces the properties of gold nanoclusters and bimetallic nanoclusters,synthesis methods and their applications in analysis and detection,and conducts research work from the following aspects:Using bovine serum albumin?BSA?as the ligand,BSA-Au/Mg NCs?Au/Mg NCs?were synthesized by a hydrothermal method.The fluorescence intensity of Au/Mg NCs is stronger than that of AuNCs without Mg element doping,and it has a better selective quenching response to Co²⁺.Based on the fluorescence response characteristics of the cluster to Co²⁺,a rapid method of detecting Co²⁺was established.The results show that when the concentration of Co²⁺is in the range of 0.5?40?M,the ratio?F₀/F?showed a good linear relationship with the concentration of Co²⁺,and the limit of detection was 0.15?M(F₀ means the fluorescence intensity of the bimetallic nanocluster solution,and F means the fluorescence intensity of the solution after adding Co²⁺,the ratio of F₀/F also represents the degree of fluorescence quenching of the clusters).This method has been successfully applied to the detection of Co²⁺in real samples such as tap water and Jialingjiang water samples.Using L-cysteine?L-Cys?as the ligand,L-Cys-Au/Ag NCs?Au/Ag NCs?were synthesized by directly reacting the ligand and the metal salt.The study founded that the fluorescence quantum yield of Au/Ag NCs is 126 times that of Au NCs,and the fluorescence can be quenched by Cu²⁺.When the concentration of Cu²⁺is in the range of 0.1?10?M and 10?50?M,the degree of fluorescence quenching?F₀/F?and the concentration of Cu²⁺has a good linear relationship,and the detection limit was 0.037?M.This method has been successfully applied to the detection of Cu²⁺in health human serum.The recovery and precision inspection results are excellent.Using 3-mercapto-1,2,4-triazole?TRO?as the ligand,TRO-Au/Ag NCs?Au/Ag NCs?were synthesized by a one-step method.The fluorescence intensity of this cluster is significantly enhanced than that of Au NCs.After doping with Ag element,the fluorescence emission peak is obviously blue-shifted,and the fluorescence can be selectively quenched by Hg²⁺.Based on the characteristics of the fluorescence response of the cluster to Hg²⁺,a fluorescent probe for detecting Hg²⁺was constructed.When the concentration of Hg²⁺is in the range of 0.5-80?M,there was a good linear relationship between the degree of fluorescence quenching?F₀/F?and the concentration of Hg²⁺,and the detection limit is 0.20?M.This method has been successfully applied to the detection of Hg²⁺in real samples such as Jialing River and Yuxiu Lake.