▎ 摘　　要

NOVELTY - Preparing covalent organic framework/graphene composite material (COF-367-Zn/rGO) comprises (i) reducing sheet-type graphene oxide (GO) with 6-10 ml of 80 % hydrazine hydrate solution at 70-90℃ for 11-12 hours, vacuum-drying at 75-85℃ for 23-25 hours to obtain flaky reduced graphene oxide (rGO), (ii) adding reduced graphene oxide, 5,10,15,20-Tetrakis(4-aminophenyl)porphyrin zinc (Zn(TAPP)), biphenyldialdehyde, mesitylene, ethanol and 6 M acetic acid aqueous solution into heat-resistant glass tube, sonicating for 30-40 minutes, then performing three cycles of degassing, sealing tube, and heating reaction at 115-120℃ for 72-75 hours, and (iii) completing reaction, preparing dark purple precipitate at bottom of tube, and centrifuging to obtain final product. USE - The method is useful in preparing covalent organic framework/graphene composite material in preparing electrochemical sensor for real-time detecting of nitric oxide and carbon monoxide (all claimed). ADVANTAGE - The material: has high specific surface area, good electrical conductivity, and highly exposed active sites, which is coated on ITO electrode to form working electrode for construction of a nitric oxide electrochemical sensor, and can apply for real-time detection of nitric oxide released by cells, which has fast response, high sensitivity, good selectivity and excellent stability in practical detection. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: electrochemical sensor for detecting nitric oxide, comprising ITO electrode and covalent organic framework/graphene composite COF-367-Zn/rGO on surface of ITO electrode. preparing electrochemical sensor for detecting nitric oxide, comprising (i) washing ITO electrode three times with toluene, acetone, ethanol, and water, and drying, (ii) preparing covalent organic framework/graphene composite COF367-Zn/rGO into uniform suspension with concentration of 2-4 mg/ml with ethanol, water and Nafion, applying 10-15 μl suspension to working electrode, and volatilizing solvent to obtain electrochemical sensor coated with a covalent organic framework/graphene composite material COF-367-Zn/rGO, where the volume ratio of ethanol, water and Nafion is 1:0.3-0.6:0.004-0.01. electrochemical sensor for detecting nitric oxide and real-time detecting of carbon monoxide. use method of electrochemical sensor for detecting nitric oxide, comprising using cyclic voltammetry, in the concentration of 0-216 μM, gradually increasing response current with increase of concentration, where the oxidation peak of nitric oxide appears at 1.1 V.