▎ 摘　　要

NOVELTY - A mycotoxin aflatoxin B1 ratio electrochemical biosensor preparing method involves separately dissolving hydrogen iodide and reduced graphene oxide in ultrapure water and storing. The non-covalent thionine is protected from light and reduced graphene oxide is treated with a cell pulverizer. The non-covalent thionine solution and the treated reduced graphene oxide dispersion are mixed, stirred and washed to obtain a non-covalent thionine and reduced graphene oxide composite material. The glassy carbon electrode is polished with alumina powder, dried in ethanol and water and in air. The prepared composite is modified to the surface of the glassy carbon electrode and dried. The prepared surface of the sensor is modified with chitosan and dried. The obtained aptamer is modified and electrostatic adsorption between the chitosan and the mycotoxin aflatoxin B1 aptamer caused the mycotoxin aflatoxin B1 aptamer to be immobilized to obtain the aflatoxin B1 ratio electrochemical biosensor. USE - Method for preparing an electrochemical biosensor for detecting a mycotoxin aflatoxin B1 ratio. ADVANTAGE - The sensor has simple preparation method, high selectivity, high sensitivity, better reproducibility and better stability and provides a better sensing platform for detecting mycotoxin aflatoxin B1 in actual samples. DETAILED DESCRIPTION - A mycotoxin aflatoxin B1 ratio electrochemical biosensor preparing method involves separately dissolving hydrogen iodide and reduced graphene oxide in ultrapure water and storing at room temperature. The non-covalent thionine is protected from light and reduced graphene oxide is treated with a cell pulverizer to improve its dispersibility in water. The non-covalent thionine solution and the treated reduced graphene oxide dispersion are mixed, stirred and washed by centrifugation to obtain a non-covalent thionine and reduced graphene.