▎ 摘　　要

NOVELTY - Preparing iron oxide-reduced graphene oxide (rGO) electrochemical sensor involves preparing iron oxide-rGO composite nanomaterials by adding deionized water to the graphene oxide, and ultrasonically treating graphene oxide to fully disperse the graphene oxide in the water to obtain a graphene oxide solution, dissolving iron chloride and ferrous chloride tetrahydrate in deionized water at a molar ratio of 2:1 to obtain a mixture of divalent and trivalent iron ions, immediately after the graphene oxide solution is vigorously stirred, slowly dropping divalent and trivalent iron ion mixture into the graphene oxide solution and ion exchange to obtain the mixture A. Modified electrode is prepared after carbon electrode is polished followed by ultrasonically processing suspension to make the iron oxide-rGO nanocomposite uniformly dispersed in deionized water, dropping 7-9 mu l ultrasonically processed suspension onto the center of the surface of the glassy carbon electrode, and drying. USE - Method for preparing iron oxide-reduced graphene oxide electrochemical sensor for detecting arsenic ions in water (claimed). ADVANTAGE - The method enables preparing the electrochemical sensor with better effect of obtaining the best current response, and detecting the concentration of trace arsenic ion in water in real time. DETAILED DESCRIPTION - Preparing iron oxide-reduced graphene oxide (rGO) electrochemical sensor involves preparing iron oxide-rGO composite nanomaterials by adding deionized water to the graphene oxide, and ultrasonically treating graphene oxide to fully disperse the graphene oxide in the deionized water to obtain a graphene oxide solution, dissolving iron chloride and ferrous chloride tetrahydrate in deionized water at a molar ratio of 2:1 to obtain a mixture of divalent and trivalent iron ions, immediately after the graphene oxide solution is vigorously stirred, slowly dropping divalent and trivalent iron ion mixture into the graphene oxide solution and ion exchange to obtain the mixture A, adding ammonia water dropwise to the mixed solution A after the ion exchange is completed, and continuously checking with the pH test paper until the pH value of the mixed solution A becomes 10, and the mixed solution B is obtained, and utilizing mixed solution B for the synthesis of iron oxide- rGO nanomaterials, utilizing water bath heating to heat mixed solution B at 75-85 degrees C, and adding hydrazine hydrate dropwise under constant stirring to reduce graphene oxide, to obtain a black solution, quickly stirring black solution at 75-85 degrees C and cooling at room temperature, washing thoroughly with 75% ethanol, and collected magnetically, and finally drying overnight at room temperature in a fume hood in a clean room to obtain the black solid that is a composite material of iron oxide nanoparticles and reduced graphene oxide, which is iron oxide-rGO nanocomposite. Modified electrode is prepared after the glassy carbon electrode is polished, placing it vertically in a dust-free box at room temperature until the deionized water on the surface of the glassy carbon electrode is completely dried, weighing an appropriate weight of iron oxide-rGO nanocomposite material and pouring into a centrifuge tube, taking a corresponding volume of deionized water and configuring into a 1mg/ml iron oxide-rGO nanocomposite suspension, followed by ultrasonically processing suspension to make the iron oxide-rGO nanocomposite uniformly dispersed in deionized water, dropping 7-9 mu l ultrasonically processed suspension onto the center of the surface of the glassy carbon electrode, and placing vertically on the surface of the glassy carbon electrode, drying in the dust box at room temperature to fully vaporize the deionized water in the suspension, and attaching iron oxide-rGO nanocomposite material to the surface of the glassy carbon electrode, thus completing the preparation of electrochemical sensor. An INDEPENDENT CLAIM is also included for an iron oxide-reduced graphene oxide electrochemical sensor, which includes a working electrode, such as glassy carbon electrode, a layer of iron oxide-reduced graphene oxide composite nano material laid on the center of the glassy carbon electrode surface, and iron oxide-reduced graphene oxide composite nanomaterials, iron oxide nanoparticles uniformly distributed on the surface of rGO and between the graphene oxide layer.