▎ 摘　　要

NOVELTY - A chitosan electrochemical biosensor comprises a polished bare glassy carbon electrode and a prepared sulfonic functional graphene-chitosan compound modified electrode, where acetylcholinesterase is immobilized on the electrodes and an electrochemical signal from an amplifier, and the residual amount of methyl parathion with electrochemical peak current is determined for establishing a standard curve of the quantitative detection of methyl parathion. USE - Chitosan electrochemical biosensor for detecting methyl parathion and phosphorus content in vegetable and fruit products. ADVANTAGE - The biosensor has high-sensitivity and strong operability to methyl parathion in phosphorus quantitative detection process.