▎ 摘　　要

NOVELTY - Preparing simple electrochemical microsensor involves preparing bare carbon fiber micro-electrode, depositing graphene oxide on the carbon fiber microelectrode surface by electro-deposition method, subjecting the electrode to electro-oxidation treatment to form a built-in correction signal, namely to obtain the CMFE/OxGO electrode, modifying the Ti3C2Tx (MXene) to the obtained CMFE/OxGO electrode, placing the modified electrode in silver nitrate solution for reduction and self-assembly to obtain CFME/OxGO/Ti3C2Tx/Ag electrode, that is simple electrochemical microsensor. USE - Method for preparing simple electrochemical micro-sensor used for detecting negative chloride ion (Cl-) (claimed). ADVANTAGE - The method enables to prepare electrochemical micro-sensor in a simple manner, reduce Ti3C2Tx to silver (Ag) nanoparticles with uniform nanometer size to self-assemble on the surface of carbon fiber filament microelectrode as the recognition unit to specifically recognize and detect chloride ion (Cl-), improve the accuracy of negative chloride ion (Cl-) detection by graphene oxide treated by the electro-oxidation method. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for detecting negative chloride ion (Cl-) with a simple electrochemical miniature sensor, which involves: (A) placing the CFME/OxGO/Ti3C2Tx/Ag electrode in the blank phosphate buffer solution; (B) using DPV method for scanning; (C) scanning requirement is -0.75-0.4 volt to obtain an oxidation peak at -500 millivolt and 112 millivolt respectively; (D) placing the electrode inthe phosphoric acid buffer solution containing 100 M negative chloride ion (Cl-), the oxidation peak at -500 millivolt keeps the peak potential unchanged, and the oxidation peak at the position of the 112 milivolt is negative to -52 milivolt; (E) placeing orderly CFME/OxGO/Ti3C2Tx/Ag electrode in phosphate buffer solution with concentration of 0 to 700 mM negative chloride ion (Cl-), the specific concentration is 0, 1, 5, 10,20, 40, 60, 80, 100, 150, 200, 250, 300, 400, 500, 600,700 mM, Ep (Ag/AgCl) peak 112 milivolt is gradually negative along with the increase of the negative chloride ion (Cl-) concentration, and Ep (OxGO) peak potential at -500 milivolt remains unchanged; (F) calculating the two oxidation peak potential difference Delta Ep (OxGO/AgCl) is proportional to the logarithm of negative chloride ion (Cl-) concentration to obtain the standard curve of the concentration and potential difference; (G) placing the CFME/OxGO/Ti3C2Tx/Ag electrode in the unknown concentration of negative chloride ion (Cl-) solution or brain microdialysis liquid or cerebral cortex or striatum or sea horse area; (H) using DPV method to scan to obtain Delta Ep(OxGO/AgCl), standard curve; and (I) getting the chloride ion concentration.