Electrochemical Sensor Based On Magnetic Particle And AuPt Alloy For Detection Of P53 Antibody

Tumor marker detection is currently a common method for tumor screening and diagnosis.Serological markers are widely used in clinical practice due to their advantages of convenience,rapid and repeated detection.About half of the tumors have mutations in the p53 gene,and the p53 antibodies produced can be detected in body fluids and can be used as markers for tumor diagnosis,recurrence and prognosis assessment.However,the current detection method has such problems as low sensitivity,high cost and many steps,so in this study,an electrochemical sensor was designed to detect p53 antibody using Fe₃O₄@aupt catalyzed H₂O₂.Methods:Firstly,the prepared alloy was stirred with amino-modified Fe₃O₄ at room temperature.The alloy and amino formed a covalent bond and fixed on the surface of magnetic particles to form a core-shell structure.Secondly,the biotin-streptomyl-avidin system was used to connect the biotin-modified secondary antibody to the amino-modified SiO₂ surface,so as to prepare labels with high impedance and increase detection sensitivity.Then,Fe₃O₄@aupt was deposited on the surface of polished glabar carbon electrode,and p53 polypeptide and p53 antibody were gradually modified for detection in phosphate buffer solution.Results:The prepared coreshell structure and the synthesized SiO₂ were characterized by electron microscope and the result showed that the material was successfully prepared;the catalytic capability of Fe₃O₄@AuPt was characterized by electrochemical sensor,and the output current difference could meet the requirements of the sensor.Cyclic voltammetry and resistance also show that the secondary antibody is successfully attached to the surface of the silicon sphere.Conclusion:Thechemical materials related to electrochemical sensor designed in this study were successfully prepared,the properties met the requirements of the sensor construction,and the detection performance of the sensor needs to be further studied,so as to provide reference for the practical application of the electrochemical sensor.