▎ 摘　　要

NOVELTY - A dual signal amplification detecting method adding graphene oxide-cadmium sulfide-molybdenum sulfide-gold dispersion to the electrode, drying, adding the thiol-modified auxiliary DNA dropwise to the electrode, incubating, removing unconjugated thiol-modified auxiliary DNA, adding ochratoxin A aptamer dropwise to the electrode, washing, removing, adding the meso-tetra(N-methyl-4-pyridyl)porphine tetratosylate is dropwise on the electrode, removing the unbound meso-tetra(N-methyl-4-pyridyl)porphine tetratosylate, inserting the photoelectrochemical biosensor, taking out the electrode to remove residual ochratoxin A, ochratoxin A aptamer and meso-tetra(N-methyl-4-pyridyl)porphine tetratosylate, adding silicon dioxide nanoparticles-hDNA dropwise to the electrode, using the three-electrode system, mixed solution, detecting the photocurrent, drawing the standard curve, carrying out the test by using the test solution instead of the ochratoxin A standard solution obtained by a standard curve. USE - Method for detecting dual signal amplification. ADVANTAGE - The method enables detecting dual signal amplification with high sensitivity and high selectivity. DETAILED DESCRIPTION - A dual signal amplification detecting method adding graphene oxide-cadmium sulfide-molybdenum sulfide-gold dispersion to the surface of the electrode, after drying, adding the thiol-modified auxiliary DNA dropwise to the surface of the electrode, incubating at 25-37 degrees C with gold-sulfur bond to the electrode, removing unconjugated thiol-modified auxiliary DNA, adding the ochratoxin A aptamer dropwise to the surface of the electrode for incubation, washing and removing the unbound ochratoxin A aptamer, adding the meso-tetra(N-methyl-4-pyridyl)porphine tetratosylate is dropwise on the surface of the electrode, removing the unbound meso-tetra(N-methyl-4-pyridyl)porphine tetratosylate after a period of time to obtain a photoelectrochemical biosensor, inserting the photoelectrochemical biosensor separately into a series of standard solutions containing different concentrations of ochratoxin A, after a period of time, the electrode is taken out to remove residual ochratoxin A, ochratoxin A aptamer and meso-tetra(N-methyl-4-pyridyl)porphine tetratosylate, adding silicon dioxide nanoparticles-hDNA dropwise to the electrode and incubating for 1-2 hours to remove residual silicon dioxide nanoparticles-hDNA, using the three-electrode system, using the mixed solution of sodium sulfide and sodium sulfite as the electrolyte, the visible light is the excitation light, detecting the photocurrent, drawing the standard curve according to the change value of the photocurrent response to the standard sample concentration, carrying out the test by using the test solution instead of the ochratoxin A standard solution and the concentration result is obtained by a standard curve.