The Fabrication And Application Of Electrochemical Sensor Basing On The Carbon Matrix Composites

With the incidence of cancer,cardiovascular disease and other major diseases increasing year by year in the world,people’s health was seriously threatened.The research showed that the quantitative detection of disease markers by effective analytical techniques is of great significance in the early clinical diagnosis.Electrochemical immunosensor combining electrochemical analysis and biosensor technology,with the advantages of rapid analysis,high sensitivity and easy operation,is a great potential detection method.In this study,the functionalized carbon-based composites were successfully synthesized and applied to the electrode modification,and the electrochemical immunosensor with good performance was constructed achieving the detection of disease markers.The main contents are as follows:（1）A label-free electrochemical immunosensor based on r GO/Cu₈Ni₂ for the sensitive detection of neuron-specific enolaseThe r GO/Cu₈Ni₂nanocomposites were synthesized by anchoring Cu Ni alloys on the surface of reduced graphene oxide（r GO）by in-situ reduction growth method,and adjusting the molar ratio of Cu Ni metal precursor during the synthesis process.Adjusting the molar ratio of the Cu Ni alloys the electronic could effectively change the effect and the local lattice structure between the Cu Ni atoms which lead to the surface of Cu Ni alloys product more catalytically active sites,thus making Cu Ni alloys exhibit enhanced catalytic performance.Moreover,owing to good electrical conductivity and the large specific surface area,the combination of r GO and Cu Ni can effectively prevent the aggregation of Cu Ni alloys,and further improve the electrical conductivity of nanocomposites.With the synergy of Cu Ni alloys and r GO the designed electrochemical immunosensor showed excellent analytical performance and the linear range of NSE detection was 500 fg/m L to 50 ng/m L,a detection limit of 137 fg/m L.（2）A sandwich-type electrochemical immunosensor based on Pt Ni@Mo O_x/NH₂-N-r GO nanocomposite for cardiac troponin I detectionUsing simple chemical reduction method,the Pt Ni@Mo O_x/NH₂-N-r GO was prepared and was used as the signal label for the quantitative detection of cardiac troponin I（c Tn I）.Due to the carrier interaction between Pt Ni NPs and Mo O_x,the active center of Pt atom surface could be refreshed and the electronic environment of Pt atom surface could be changed,making Pt Ni NPs@Mo O_x exhibited excellent stability and electrocatalytic performance.Furthermore,N-doping and amination treatment of graphene could enhance the hydrophilicity and conductivity of NH₂-N-r GO,and was more conducive to the anchoring of a large amount of Pt Ni@Mo O_x to its surface.Using Au NPs/NH₂-GS（graphene supported gold nanoparticle composite）as the sensing platform,could not only improve the electron transfer rate on the electrode surface,but also effectively load more Ab₁ through chemical bonds.Under the optimal condition,the designed immunosensor showed good reproducibility,selectivity and stability.The linear range for c Tn I detection was 100 fg/m L to 50 ng/m L,the detection limit was 33.4 fg/mL.