Application Of Palladium Nanoenzyme Complex In Electrochemical Biosensor

As a global disease with high morbidity and mortality,cancer needs an effective diagnostic method.The early diagnosis of cancer is generally based on the content of tumor markers.Therefore,the detection of tumor markers is very important for the detection of cancer.In recent years,many detection methods have emerged,and electrochemical detection has attracted much attention because it combines electrochemical technology with biosensing technology to achieve sensitive detection.Electrochemical immunosensors based on the specific recognition of antigen-antibodies convert biochemical signals into electrical signals through electrochemical workstations.It can achieve biomolecule detection and acquisition of biological information.In this paper,two-dimensional nanomaterials and palladium-based nanoenzymes are applied to prepare composite nanomaterials for electrochemical immunosensor construction,which exhibits good catalytic activity and achieves quantitative detection of tumor markers.The main research contents are as follows:1. The graphene oxide was synthesized by hydrothermal method,and the porous Pd nanospheres functionalized by glutathione-protected Au nanoparticles?G-Au NPs?were loaded on graphene oxide?GO?by a self-assembly method to obtain G-Au@Pd/GO nanoenzymes.Glutathione-protected gold nanoparticles not only have good water solubility,but also facilitate the capture of antibodies.G-Au@Pd has larger specific surface area,and GO can effectively load G-Au@Pd and enhance electrical signals.The G-Au@Pd/GO nanoenzymes were applied for the detection of carcinoembryonic antigen,with the detection range of 10 fg·m L^-1-100 ng·m L^-1 and the detection limit of 3.2 fg·m L^-1?S/N=3?.2. PdCu tripods functionalized porous graphene?PdCu TPs/P-GN?nanoenzymes were prepared by in situ reduction of PdCu tripods?PdCu TPs?onto porous graphene?P-GN?,which was used for the construction of electrochemical immunosensors.In the detection of hepatitis B e antigen?HBe Ag?,much higher electrochemical activity was obtained because of more active sites,achieving the detection range of 60 fg·m L^-1-100 ng·m L^-1 and the detection limit of 20 fg·m L^-1?S/N=3?.3. Molybdenum disulfide nanosheets?MoS₂?were prepared by hydrothermal method.PtPd nanocubes@MoS₂ nanozymes?PtPd NCs@MoS₂?was prepared by in situ reduction of PtPd nanocubes?PtPd NCs?on molybdenum disulfide nanosheets?MoS₂?.PtPd nanocubes exhibit good electrical conductivity and catalytic activity,and pleated molybdenum disulfide has increased active area.The composite nanoenzyme was used for the detection of hepatitis B surface antigen?HBs Ag?with the detection range of 32fg·m L^-1-100 ng·m L^-1 and the detection limit of 10.2 fg·m L^-1?S/N=3?.The functionalized palladium nanoenzyme applied to construct the electrochemical immunosensor not only exhibits good peroxidase enzyme performance,but also has good electrocatalytic activity and biocompatibility.For the detection of tumor markers,it shows wide linear range,low detection limit,good reproducibility,stability and selectivity.Comparing the test results with the real sample test methods of the hospital,it shows good consistency and potential for clinical testing.