▎ 摘　　要

NOVELTY - An electrochemical sensor construction method involves adding reduced graphene oxide to ethylene glycol, mixing, dissolving, adding iron(III) acetylacetonate, ultrasonically processing the mixture for 30-40 minutes, adding 1.4-1.6 g amine acetate, stirring for 30-50 minutes, transferring obtained mixed solution to reaction kettle, reacting at 190-210 degrees C for 22-26 hours, cooling to room temperature, performing solid-liquid separation to obtain solid phase, washing the solid phase using water and ethanol, dissolving and dispersing the solid phase using water, making up to 2-4 mg/ml, obtaining graphene oxide/magnetite solution followed by obtaining reduced graphene oxide/magnetite/cuprous oxide solution, pretreating magnetic glassy carbon electrode, performing electrochemical scanning, recording signal changes and establishing standard curve between the electrochemical signal and sodium hydrosulfide concentration of the magnetic hybrid nanomaterials. USE - Method for constructing electrochemical sensor that is utilized for detecting endogenous hydrogen sulfide (claimed). ADVANTAGE - The method enables constructing electrochemical sensor with low detection limit and high accuracy. DETAILED DESCRIPTION - An electrochemical sensor construction method involves adding reduced graphene oxide to ethylene glycol, mixing, dissolving, adding iron(III) acetylacetonate, ultrasonically processing the mixture for 30-40 minutes, adding 1.4-1.6 g amine acetate, stirring for 30-50 minutes, transferring obtained mixed solution to reaction kettle, reacting at 190-210 degrees C for 22-26 hours, cooling to room temperature, performing solid-liquid separation to obtain solid phase, washing the solid phase using water and ethanol, dissolving and dispersing the solid phase using water, making up to 2-4 mg/ml, obtaining graphene oxide/magnetite solution, adding the graphene oxide/magnetite solution to 0.01-0.012 g/ml copper nitrate solution, ultrasonically processing for 30-40 minutes, uniformly mixing, adding 80-100 mu l 0.035-0.04 mol/l sodium hydroxide solution, stirring for 30-50 minutes, adding 85-90 mol/l, 400-450 ml hydrazine hydrate solution, stirring for 40-50 minutes, performing solid-liquid separation, obtaining solid phase, washing the solid phase using water, drying, re-dispersing in water to obtain 2-3 mg/ml reduced graphene oxide/magnetite/cuprous oxide solution, polishing magnetic glassy carbon electrode using alumina powder with particle diameter of 0.4-0.6 mm and 0.025-0.03 mm respectively, washing the polished electrode using ethanol and water, performing cyclic voltammetry, polishing, when potential difference between oxidation peak and reduction peak is less than 90 mV, cleaning the polished electrode using ethanol and water, drying the electrode using nitrogen or argon, adding certain amount of reduced graphene oxide/magnetite/cuprous oxide solution to series of different concentrations of sodium hydrosulfide and 5-7 wt.% ammonia water, reacting for certain period of time, adsorbing magnetically mixed nanomaterials after reacting with magnet, removing supernatant, separating magnetic hybrid nanomaterials, dispersing in ultrapure water, drip-coating on electrode surface, performing electrochemical scanning, recording signal changes and establishing standard curve between the electrochemical signal and sodium hydrosulfide concentration of the magnetic hybrid nanomaterials. An INDEPENDENT CLAIM is also included for an electrochemical sensor prepared by the method.