Preparation And Analytical Application Of Pt-based Peroxidases

With the development of nanoenzymes,there have been a large number of literature reports on the research of Pt-based nanoparticles with mimic enzyme activity.Pt-based nanoparticles are nanomaterials based on metal Pt because of their adjustable size and morphology,has broad application prospects in catalysis,sensing imaging,in vitro diagnostics and biomedicine.Pt-based nanoparticles usually have the following main mimic enzyme activities,such as oxidase,peroxidase,superoxide dismutase,catalase and so on.In addition,this kind of nanoparticle not only has one enzyme activity,some nanoparticles also have two or more mimic enzyme activities.Although Pt-based nanomaterials have been developed rapidly due to their good application prospects.However,the research on improving the utilization of Pt-based nanoenzymes and increasing the catalytic activity needs further attention.The research content of this paper is mainly to prepare two Pt-based nanomaterials with different morphologies,explore the peroxidase activity of these two Pt-based nanomaterials and apply them to analysis and detection.Firstly,the hollow bowl-shaped nano-Pd₃Pt with peroxidase-like activity was synthesized in one step by hydrothermal method,and its size,morphology and other properties were characterized.In the presence of hydrogen peroxide,Pd₃Pt nanoparticles can quickly catalyze the conversion of colorless TMB to blue ox TMB,so they have excellent peroxidase activity.This is because the structure has a larger exposed area,which makes catalytically active sites increase.Further research found that Ag⁺can weaken the peroxidase activity of nano-Pd₃Pt.On this basis,we established a simple and fast colorimetric method to detect the Ag⁺content in water samples.Secondly,the study found that cysteine can reduce the peroxidase activity of Pd3Pt nanoparticles,thereby further constructing a new method for colorimetric detection of cysteine in biological samples.Finally,in order to obtain a larger specific surface area and improve the catalytic performance,we prepared flower-like COF-loaded nano-Pt(COF@Pt)by chemical reduction at room temperature,and the flower-like COF@Pt was measured by transmission electron microscope,scanning electron microscope and physical adsorption instrument.Characterize properties such as morphology,size and specific surface area.The study found that flower-like COF@Pt has high-efficiency peroxidase activity,which is due to the large number of catalytic active sites in the structure.At the same time,it was found that tannic acid can significantly inhibit the peroxidase activity of COF@Pt.Based on this phenomenon,we developed a new colorimetric detection method for tannic acid in tea.