Preparation Of PtCu₃ Nanozyme And Functionalization Of Metal-porphyrin MOF And Their Application In Chemical Sensors

Chemical sensors have incomparable advantages and broad application prospects in biomedical analysis,imaging and environmental protection due to their simplicity,portability and high sensitivity.In order to improve the application of biosensors in food monitoring and biomedical fields,different nanomaterials were synthesized and their unique catalytic properties were used to construct biosensors based on UV-Vis spectrophotometric and electrochemical methods for the instant detection of organophosphorus pesticides on fruit surfaces and thrombin in human serum in this thesis.The details of the study are as follows:1.In this chapter,Pt Cu₃ alloy nanocrystals with irregular polyhedral morphology were synthesized,and a colorimetric biosensor was constructed for the sensitive detection of organophosphorus pesticides using the peroxidase-like activity of Pt Cu₃alloy and the catalytic activity of acetylcholinesterase.The sensor has the advantages of wide linear range(1 ng m L^-1-10 mg m L^-1)and low detection limit(0.5 ng m L^-1).Moreover,based on the above-mentioned colorimetric principle,a visual test paper for the detection of organophosphorus pesticides was constructed,and the qualitative and quantitative analysis of organophosphorus pesticide residues on the surface of fruits can be performed by using the color recognition software on cell phones,thus expanding the application of the sensor in real life.2.In this chapter,we proposed an electrochemical biosensor with a"sandwich structure"to achieve ultra-sensitive detection of thrombin in human serum.Apt1 can bind specifically to the first site of thrombin,and the other site of thrombin can bind specifically to Apt2.Pt Cu₃ alloy nanocrystals,which is linked to Apt2 by a Pt-N bond,can electrocatalyze H₂O₂ to produce a significant reduction current.As a result,the reduction current in the system is enhanced with increasing thrombin concentration,thus enabling the electrochemical detection of thrombin.The method has the advantages of wide linear range(0.00001-32n M),low detection limit(0.00001n M),and high sensitivity,good reproducibility and stability,which provides an efficient and accurate method for the detection of thrombin in human serum.