▎ 摘　　要

NOVELTY - Detecting insulin electrochemically involves preparing composite nanoparticles by co-precipitating and reducing ferrous ions, ferric ions and graphene by hydrazine hydrate to form composite. The obtained composite is added with aniline and ruthenium sulfate to obtain composite nanoparticles. Imprinted prepolymer molecule is prepared by mixing functional monomer, insulin, composite nanoparticles and phosphate buffer saline to obtain mixed solution. The mixed solution is sealed after nitrogen filling, and placed in dark at room temperature for 3-6 hours. USE - Method for detecting insulin electrochemically (claimed). ADVANTAGE - The method enables to detect insulin electrochemically in sensitive, rapid, simple and cost-effective manner with strong anti-interference ability, good stability and reproducibility. DETAILED DESCRIPTION - Detecting insulin electrochemically involves preparing composite nanoparticles by co-precipitating and reducing ferrous ions, ferric ions and graphene by hydrazine hydrate to form composite. The obtained composite is added with aniline and ruthenium sulfate to obtain composite nanoparticles. Imprinted prepolymer molecule is prepared by mixing functional monomer, insulin, composite nanoparticles and phosphate buffer saline to obtain mixed solution. The mixed solution is sealed after nitrogen filling, and placed in dark at room temperature for 3-6 hours. The mixed solution is pre-assembled to obtain molecular imprinted prepolymer solution. The obtained molecular imprinted prepolymer solution is added with ammonium persulfate initiator for polymerizing at 0-20 degrees C under stirring to obtain polymerized mixture. The obtained polymerized mixture is evaporated to remove supernatant, and then washed with water. The washed mixture is added with acetic acid-acetonitrile solution to remove template molecule to obtain conductive molecular imprinted nanoparticles. The obtained conductive molecular imprinted nanoparticles are placed in phosphate buffer saline solution containing insulin to be tested, and agitated and adsorbed to obtain insulin-MIPs solution. The obtained insulin-MIPs solution is placed in reaction cell, and inserted into magnetic glassy carbon electrode with removable segmented magnetic core. The nanoparticles are magnetically enriched and controlled on the electrode surface. Electrochemical determination is performed by measuring current response.