▎ 摘　　要

NOVELTY - Construction of visual electrochemiluminescent sensor involves laser etching a visualization area and detection area on cleaned indium tin oxide glass, dispersing solid product tris(bipyridine)ruthenium(II)-bismuth oxyiodide composite in deionized water to obtain dispersion, applying dispersion droplet to visualized area, dripping Nafion (RTM: sulfonated tetrafluoroethylene based fluoropolymer-copolymer) solution to form uniform film fixing material, drying to obtain a visualized region, spin-coating graphene oxide solution in detection area and leaving still at room temperature to form a transparent film, using phosphate-buffered saline as solvent to prepare ochratoxin A (OTA) aptamer solution, dripping OTA aptamer solution on the film, washing, dripping bovine serum albumin solution to block non-specific active sites, to obtain aptamer-modified detection region and constructing the aptamer-modified detection region aptamer and visualized region. USE - Construction of visual electrochemiluminescent sensor used for detecting ochratoxin (claimed) in food product such as corn, wheat, oat and other cereal related products. ADVANTAGE - The method provides fast, simple and miniaturized, portable visualization electrochemical luminous aptamer sensor with flexible use mode and improved immobilization enhancement effect of tris(bipyridine)ruthenium(II)-bismuth oxyiodide composite, without using traditional photoelectric multiplication amplification strategy. The sensor can realize rapid on-site detection. DETAILED DESCRIPTION - Construction of visual electrochemiluminescent sensor involves (i) adding ruthenium bipyridine into a bismuth oxyiodide dispersion, stirring to form a uniformly dispersed aqueous solution (A), transferring the aqueous solution (A) to an ultrasonic machine for ultrasonication, washing and drying to obtain solid product tris(bipyridine)ruthenium(II)-bismuth oxyiodide composite, (ii) after ultrasonically cleaning of indium tin oxide glass in toluene, acetone, ethanol and water in turn, drying in nitrogen flow, electrochemically cleaning of indium tin oxide glass by cyclic voltammetry to remove impurities and organic pollutants that are optionally adsorbed on the surface, and finally drying with nitrogen gas, laser etching the visualization area and detection area on cleaned indium tin oxide glass, (iii) dispersing the solid product obtained in step (i) in deionized water to obtain dispersion, applying the dispersion droplet to the visualized area of indium tin oxide glass, and dripping Nafion (RTM: sulfonated tetrafluoroethylene based fluoropolymer-copolymer solution to form a uniform film fixing material, drying in an oven to obtain a visualized region, (iv) spin-coating graphene oxide solution in the detection area and leaving still at room temperature to form a transparent film, using phosphate-buffered saline as solvent to prepare ochratoxin A (OTA) aptamer solution, dripping OTA aptamer solution on the transparent film, after a certain period of incubation, washing with phosphate-buffered saline to remove any unbound aptamer, and then dripping bovine serum albumin solution to block non-specific active sites, to obtain aptamer-modified detection region and (v) constructing the aptamer-modified detection region aptamer obtained in step (iv) and visualized region in step (iii). An INDEPENDENT CLAIM is included use of the visualized electrochemiluminescent aptamer sensing device for detecting ochratoxin.