▎ 摘　　要

NOVELTY - Double-electrode photoelectrochemical aptamer sensor comprises a first conductive glass electrode used as a working electrode and a second conductive glass electrode used as a counter electrode in a double-electrode system. The surface of the reaction end of the first conductive glass electrode is modified with a graphite phase carbon nitride/tungsten oxide/manganese dioxide ternary composite material. The graphite phase carbon nitride/tungsten oxide/manganese dioxide ternary composite material uses graphite phase carbon nitride nanosheets as a carrier. Tungsten oxide nanoparticles and manganese dioxide nanosheets are supported on the graphite phase carbon nitride nanosheets. The surface of the reaction end of the second conductive glass electrode is modified with a composite film. The composite film is composed of reduced graphene oxide loaded with gold nanoparticles. The surface of the composite membrane is self-assembled with specific aptamer probes. USE - The sensor is useful in detecting antibiotics (claimed). ADVANTAGE - The sensor: has high stability, long service life, strong anti-interference ability, high detection sensitivity, wide detection range, low detection limit, etc.; and can realize the specific detection of pollutants (e.g. antibiotics) in media e.g. water bodies and organisms with high utilization rate, high use value and excellent application prospects. The method: has simple process, convenient operation, and high production efficiency; and is safe, economical, environmentally friendly, suitable for large-scale preparation, and good for industrial application. DETAILED DESCRIPTION - Double-electrode photoelectrochemical aptamer sensor comprises a first conductive glass electrode used as a working electrode and a second conductive glass electrode used as a counter electrode in a double-electrode system. The surface of the reaction end of the first conductive glass electrode is modified with a graphite phase carbon nitride/tungsten oxide/manganese dioxide ternary composite material. The graphite phase carbon nitride/tungsten oxide/manganese dioxide ternary composite material uses graphite phase carbon nitride nanosheets as a carrier. Tungsten oxide nanoparticles and manganese dioxide nanosheets are supported on the graphite phase carbon nitride nanosheets. The surface of the reaction end of the second conductive glass electrode is modified with a composite film. The composite film is composed of reduced graphene oxide loaded with gold nanoparticles. The reduced graphene oxide loaded with gold nanoparticles uses reduced graphene oxide as a carrier. The surface of the reduced graphene oxide is loaded with gold nanoparticles. The surface of the composite membrane is self-assembled with specific aptamer probes. INDEPENDENT CLAIMS are also included for: (1) preparing the sensor, comprising (1) coating the reduced graphene oxide suspension loaded with gold nanoparticles on the reaction end surface of the second conductive glass electrode to obtain a second conductive glass electrode modified with reduced graphene oxide loaded with gold nanoparticles, (2) dropping the specific aptamer probe solution onto the reaction end surface of the second conductive glass electrode modified with reduced graphene oxide loaded with gold nanoparticles obtained in step (1), adding it to the 6-mercaptoethanol solution for incubation, so that the specific aptamer probe is fixed on the reaction end surface of the second conductive glass electrode through the gold-sulfhydryl covalent bond, and obtaining specific aptamer probe and second conductive glass electrode modified with reduced graphene oxide loaded with gold nanoparticles, and (3) coating the graphite phase carbon nitride/tungsten oxide/manganese dioxide ternary composite material suspension on the surface of the reaction end of the first conductive glass electrode, obtaining a first conductive glass electrode modified by a ternary composite material of graphite phase carbon nitride/tungsten oxide/manganese dioxide as a working anode, using the specific aptamer probe in step (2) and the second conductive glass electrode modified with reduced graphene oxide loaded with gold nanoparticles as the counter electrode, and constructing double-electrode photoelectrochemical aptamer sensor; and (2) detecting antibiotics, comprising adding the antibiotic solution dropwise to the specific aptamer probe and the reaction end surface of the second conductive glass electrode modified with reduced graphene oxide loaded with gold nanoparticles for reaction, making the specific aptamer probe in the double-electrode photoelectrochemical aptamer sensor specifically recognize and capture antibiotics as a counter electrode, using the first conductive glass electrode modified by the ternary composite material of graphite phase carbon nitride/tungsten oxide/manganese dioxide as the working electrode to establish double-electrode system, connecting the double-electrode system to the electrochemical workstation, using the chronoamperometry to test under intermittent light, constructing the detection linear regression equation according to the relationship between the antibiotic concentration and the photocurrent change, and calculating the concentration of the antibiotic in the solution to be tested according to the detection linear regression equation.