Fabrication Electrochemical Immunosensor Based On Nobel Metal Modified Co-based Metal Organic Framework Derivatives Composite Structure And Their Electronchemical Performance

Prostate cancer is the second most common cancer malignancy for male,which maybe cause seriously threaten the physical health of men.Prostate specific antigen（PSA）is a kind of glycoprotein secreted by human prostate tissue,which has been widely used in the screening,diagnosis,monitoring and treatment of prostate-related diseases.Therefore,it is very important to develop the advanced analysis technology for detection of prostate-specific antigen.Electrochemical immunosensor,as a new type of biosensor,combine specific immunologic recongintion reactions and electrochemical sensing techniques,which exhibits many advantages including rapid response,high selectivity,low cost and so on.Electrochemical immunosensor is promising for environmental monitoring,food safety and biomedicine applications.Metal organic framework,as porous crystal material,is constructed by organic linkers and metal ions or clusters.Because of the large specific surface area,high porosity and flexible structures,metal organic frameworkis suitable for as the sensing material of electrochemical immunosnesor.Therefore,we selected the Co-MOF-based derivatives as the sensing material in this thesis,and combined with noble metal nanoparticles and carbon-based nanostrctures,which constructed label-free three different kinds of electrochemical immunosensors for PSA detection.The mainly thesis contents and measured experimental results are as follows:（1）Firstly,the different contents of Pd nanoparticles modified ZnCo-MOF derivatives（PdNPs@ZnCo-MOF）hollow microcage structures have been successfully synthesized through solvothermal method.The morphologies of ZnCo-MOF nanostructures were observed using scanning electron microscope（SEM）,and the electrochemical immunosensor was fabricated based on the PdNPs@ZnCo-MOF derivatives.The electrochemical performances of sensor were performed using cyclic voltammetry（CV）and differential pulsed voltammetry（DPV）techniques.The obtained results demonstrated that 2 mol%PdNPs@ZnCo-MOF based sensor shows linear range from 0.05 ng/mL to 100 ng/mL,which also exhibits good reproducibility toward prostate specific antigen detection.（2）Secondly,the Au nanoparticles modified ZnCo-MOF derivatives/reduced graphene（Au NPs/ZnO-Co₃O₄/r GO）composite structures were prepared based on the formed research work,and electrochemical immunosensor was also fabricated toward PSA detection.The morphologies of Au NPs/ZnO-Co₃O₄/r GO nanostructures were observed using SEM、XPS and XRD.Meanwhile,the parameters of the mass ratio between ZnO-Co₃O₄ and graphene,modification contents of Au nanoparticles,loading amount of ZnO-Co₃O₄/GO and incubation time of antigen and antibody were optimized to evaluate the electrochemical performances.Under the optimum conditions,the as-prepared electrochemical immunosensor exhibits wider detection range（100 fg/mL～200 ng/mL）,a lower detection limit（0.06 pg/mL）and good reproducibility,selectivity and stability.（3）Thirdly,the electrochemical immunosensor based on the Au nanoparticles modified Co-MOF derivatives/carbon nanotube（Au NPs/Co₃O₄/CNTs）nanostructures were prepared toward PSA detection.Under the optimum conditions,the as-prepared electrochemical immunosensor displays wide linear of detection（500 fg/mL～200 ng/mL）and lower detection limit（0.23 pg/mL）,which is potential used for practical sample application.