The Fabrication And Application Of Electrochemical Sensor Based On CuS Nanocomposites

Cancer has become very important public health problem,early detection and treatment are effective means to increase the cure rate of cancer.Therefore,developing a rapid,sensitive and convenient detection method has important academic significance for the diagnosis and treatment of cancer.In this work,transition metal sulfide nanocomposites were designed based on different morphologies and structures,and their electrochemical properties were studied and applied to electrochemical sensing to achieve sensitive detection of tumor markers.The main research contents are as follows:（1）A sandwich-type electrochemical immunosensor was designed for sensitive detection of CEA based on three-dimensional porous Pt Cu nanocrystals loaded on amino-functionalized copper sulfide nanospheres（P-Pt Cu/FCu S NPs）as signal amplification materials and the gold nanoparticles loaded on sulfonated multi-walled carbon nanotubes（Au/s-MWCNTs）as the substrate material.The three-dimensional self-supporting porous structure Pt Cu provided sufficient active sites to increase contact area for reaction with redox molecules,and created a microenvironment for biomolecules to maintain their stability and activity.Amino-functionalized copper sulfide nanospheres（FCu S NPs）with peroxidase activity,large surface area,and abundant amino groups,were used as the supporting material to load the P-Pt Cu,which significantly improved analyze performance of the immunosensor.The gold nanoparticles loaded on sulfonated multi-walled carbon nanotubes（Au/s-MWCNTs）were used as platform,which not only provided large specific surface area to increase the loading of primary antibodies,but also accelerated electron transfer on the surface of electrode.Under optimized experimental conditions,the electrochemical immunosensor can achieve quantitative detection of CEA with linear range of 10 fg/m L～10 ng/m L and a detection limit of 3.3 fg/m L.（2）A novel signal amplification electrochemical immunosensor was designed based on MoS₂/Cu S-Au as substrate material and mulberry-shaped Au@Pt Pd porous nanorods（Au@Pt Pd MPs）as markers.The combination of MoS₂ and Cu S overcomed the aggregation phenomenon caused by strong van der Waals force in the MoS₂ layered crystal and improved the performance of MoS₂.More importantly,the tremella-liked MoS₂/Cu S nanocomposite had a larger surface area and more active sites,which significantly improved the analytical performance of the electrochemical immunosensor.The Au NPs introduced by the in-situ reduction method effectively increase the electron transporting ability of the electrode surface,and a large number of primary antibodies（Ab₁）are coupled through the Au-N bond.In addition,the Au@Pt Pd MPs nanocomposites with mulberry-like porous rod-like core-shell structure was synthesized by hydrothermal synthesis.Its unique porous core-shell rod structure and trimetallic composition show excellent catalytic and stability,so the sensitivity of the constructed sensor has been further improved.Under optimal experimental conditions,the linear range of the immunosensor was 50 fg/m L～100 ng/m L,and the detection limit was 16.7 fg/m L.The constructed immunosensor had good analytical performance,including good stability,reproducibility and selectivity,and had been successfully applied to the detection of CEA in human serum.In the work,the two electrochemical immunosensors designed and developed for detecting carcinoembryonic antigens have opened up new ideas for sensitive detection of tumor markers,provided experimental evidence and methods for the clinical diagnosis of cancer,and laid the foundation for the practical medicalization of the sensors.