Preparation Of MoS₂,Research And Applications Of Its Peroxidase-like Property

Due to the high catalytic efficiency,high specificity catalytic properties of natural enzyme,they were widely used in the pharmaceutical synthesis,clinical testing,environmental monitoring,agriculture and other fields.Unfortunately,the nature enzymes resistance to acid,alkali and high temperature,bad stability,purification cumbersome and expensive,so that,it's widely applications were limited.Therefore,by using the chemical method synthesizing materials with catalytic properties similar to nature enzyme,it has a significance to exploit a new material to replace the traditional nature enzyme is very necessary.In recent years,with the development and research of nanotechnology,nanomaterials are widely applied in different fields owing to their surface effect and quantum size effect.But,their catalytic activity has been neglected for a long time.Since Yan report the magnetic iron oxide nanoparticles possess peroxidase-like catalytic activity in 2007,therewith metal oxide,metal molybdenum sulfide and MOF nanomaterials displayed intrinsic peroxidase-like activity.Compared with nature enzyme,peroxidase-like enzyme has several advantages:high catalytic performance,good stability against stringent conditions,synthesis rout was simple and low-cost.Based on the above content,this study was concentrated on the development of different morphology of MoS₂ peroxidase-like enzyme,study the catalytic mechanism.For further,applied in the field of electrochemistry and electroluminescent biological sensing,used for detection of tumor markers and oligonucleotide sequence.The main research is as follows:?1?The MoS₂-Au was synthesized by a simple method,which could catalyze the oxidation of TMB to produce blue color in the presence of H₂O₂,the demonstrated MoS₂nanosheets possessed peroxidase-like catalytic activity.Which could catalyze H₂O₂ to produce stability current,the catalytic performance of MoS₂-Au was higher than MoS₂ du to the high electrical conductivity of Au NPs.A new immunosensor for the detection of CEA was developed,based on the intrinsic peroxidase activity of MoS₂-Au.MoS₂-Au was immobilized the primary antibodies,and the second antibodies were assembled on the surface of Ag NPs-GOx.Detection was achieved by measuring the current intensity when the concentrations were different with electrochemical analysis.This method was simple,good reproducibility and low-cost,can be used in the detection of tumor markers in serum samples.?2?In this study,preparation Au-paper working electrode,synthesis MoS₂ nanosheets with a small particle size,experimental results showed the MoS₂ nanosheets with a small particle size had a better catalytic activity of H₂O₂ and peroxidase-like catalytic activity more stable compared with larger MoS₂ nanosheets.Preparation of a portable type of sandwich immunosensor based on the peroxidase-like catalytic activity of MoS₂ detecting the concentration of CA125.This paper chip sensor can be used in clinical tumor markers of real-time detecting,and this simple operation analysis method has a good application prospect in clinical diagnosis.?3?The prepared MoS₂ nanosheets applied in DNA sensors,MoS₂ nanosheets can quenched the ECL of Cd S/Zn S in the system of QDs-H₂O₂.Fabrication electroluminescence sensor used for detecting the content of oligonucleotide sequence based on the above theory.This method easy operate,high sensitivity and good selectivity,it can be used for detecting the concentration of DNA in serum samples.MoS₂ peroxidase-like enzyme could be used as a powerful tool in biotechnology and genetic diagnose,it will have a very good application potential in clinical diagnosis.?4?To enhance the effective catalytic specific surface area of MoS₂,and then,3D-flower MoS₂ microspheres were synthesized by a one-step hydrothermal method.The catalytic performance of 3D-flower MoS₂ microspheres was higher than MoS₂ nanosheets due to the large effective catalytic specific surface area.In this system,a novel ECL immunosensor was built based on luminol luminescent reagents to detect tumor markers of PSA.The ECL intensities of the immunosensors were changed when the concentrations of PSA were different,this method was simple for PSA detection with a linear range from 0.001 ng·m L^-1 to100 ng·m L^-1,and a detection limit of 0.28 pg·m L^-1.The remarkable high catalytic capability could allow the MoS₂ to replace conventional peroxidase-based assay systems.The new,robust and convenient assay systems can be widely utilized for the identification of other target molecules.