▎ 摘　　要

NOVELTY - Preparation of gold/silver/gold (Au/Ag/Au)-labeled carcinoembryonic antigen (CEA) electrochemical immunosensor comprises pretreating glass carbon electrode, applying nitrogen-doped graphene/carcinoembryonic antigen-first antibody complex dispersion liquid droplets on electrode surface, and post-treating; applying bovine serum albumin solution on electrode surface and post-treating; dropping CEA standard solution on electrode surface and post-treating; and dropping Au/Ag/Au-labeled CEA secondary antibody on electrode surface and post-treating. USE - Method for preparing Au/Ag/Au-labeled electrochemical immunosensor for CEA detection (claimed). DETAILED DESCRIPTION - Preparation of Au/Ag/Au-labeled CEA electrochemical immunosensor comprises: (A) polishing glass carbon electrode (GCE) having diameter of 4 mm with alumina polishing powder, respectively ultrasonically cleaning with ethanol and ultrapure water for 3 minutes, nitrogen drying, applying 6-10 mu L nitrogen-doped graphene/carcinoembryonic antigen-first antibody complex (NG-Ab1) dispersion liquid droplets on electrode surface, incubating in refrigerator at 4 degrees C for 12 hours, and washing with phosphate buffered saline solution having pH of 7.4 to obtain Ab1-NG/GCE; (B) applying 10 mu L 1-3 wt.% bovine serum albumin (BSA) solution on electrode surface, incubating at 37 degrees C for 1 hour, sealing non-specific binding sites, and washing with PBS solution to obtain BSA/Ab1-NG/GCE; (C) dropping 10 mu L 0.01-10 ng/mL CEA standard solution for antibody specificity identification on electrode surface, incubating at 37 degrees C for 60 minutes, and washing with PBS solution to obtain CEA/BSA/Ab1-NG/GCE; and (D) dropping 6-10 mu L Au/Ag/Au-labeled CEA secondary antibody (Ab2-Au/Ag/Au) on electrode surface, incubating at 37 degrees C for 60 minutes, and washing with PBS buffer solution. An INDEPENDENT CLAIM is included for application of electrochemical immunosensor for CEA detection, including using Ab2-Au/Ag/Au/CEA/BSA/Ab1-NG/GCE as working electrode, silver/silver chloride electrode as reference electrode and platinum electrode as counter electrode in electrolytic cell containing 3.5 mM hydroquinone, 1 mM hydrogen peroxide and 10 mL 0.1 M PBS buffer solution, and using electrochemical working station to test; detecting series of different concentrations of CEA standard solution by differential pulse voltammetry under scanning potential of - 0.4 to 0.8 V, recording differential pulse voltammetry curve, and drawing working curve according to obtained logarithm of current value and CEA concentration; and detecting sample solution by replacing CEA standard solution.