▎ 摘　　要

NOVELTY - Method for preparing an immunosensor based on graphene loaded with tantalum carbide (TaC) and gold-coated octahedral silver nanoparticles, involves grinding glass carbon electrode with aluminum oxide polishing powder, washing, forming an electrodeposition gold substrate on the electrode surface, rinsing with ultra-pure water, drying, adding tumor marker capture antibody, bovine serum albumin solution, tumor marker antigen solution and graphene loaded with TaC and gold-coated octahedral silver nanoparticles containing solution, rinsing, drying, and storing product. USE - The method is useful for preparing an immunosensor based on graphene loaded with TaC and gold-coated octahedral silver nanoparticles which is used for detecting tumor marker. The tumour marker is chosen from cancer antigen(CA)199 and CA125 (all claimed). DETAILED DESCRIPTION - Method for preparing an immunosensor based on graphene loaded with tantalum carbide (TaC) and gold-coated octahedral silver nanoparticles, involves (a) grinding glass carbon electrode (diameter of 3 mm) with aluminum oxide polishing powder, and washing with ultra-pure water, (b) placing the electrode in a 0.8-1 %mass chloroauric acid solution, processing at -0.2 V for 30 seconds, forming an electrodeposition gold substrate on the electrode surface, rinsing with ultra-pure water and drying the coated surface, (c) continuously adding 6 mu l 10-15 mu g/ml tumor marker capture antibody to the electrode surface, rinsing with ultra-pure water, drying and placing in a refrigerator at 4 degrees C to store, (d) continuously adding 3 mu l 1-3 mg/ml bovine serum albumin solution to the electrode surface, rinsing with ultra-pure water, drying and placing in a refrigerator at 4 degrees C to store, (e) continuously adding 6 mu l 0.0005-40 ng/ml tumor marker antigen solution with different concentrations to the electrode surface, rinsing with ultra-pure water, drying and placing in a refrigerator at 4 degrees C to store, and (f) continuously adding 6 mu l 3-5 mg/ml graphene loaded with TaC and gold-coated octahedral silver nanoparticles containing detection antibody incubation solution in a dropwise manner to the electrode surface, rinsing with ultra-pure water, drying, placing in a refrigerator at 4 degrees C to store and obtaining product. An INDEPENDENT CLAIM is included for use of the immunosensor based on graphene loaded with TaC and gold-coated octahedral silver nanoparticles, for detecting tumor markers, by (a) using electrochemical workstation to test the three-electrode system, saturated calomel electrode as reference electrode, platinum wire electrode as auxiliary electrode and prepared immunosensor as working electrode, where the test is performed using 10 ml 50 mmol/l phosphate buffer solution (pH 5-8), (b) performing time-current method to detect analyte with input voltage of -0.4 V, sampling interval of 0.1 seconds and running time of 400 seconds, and (c) when the background current is stabilized, injecting 10 mu l 5 mol/l hydrogen peroxide solution into the 10 ml 50 mmol/l phosphate buffer solution (pH 7.4), processing for 50 seconds, and recording current change.