▎ 摘　　要

NOVELTY - Electrochemical sensor with graphene modified electrode for quickly detecting sulfide comprises glassy carbon electrode as a carrier, and carrier loaded with 50-60 mu g/cm2 graphene as an identification element. USE - The electrochemical sensor is useful in environmental monitoring, water quality analysis, and detecting the metabolic products of corrosive microorganisms (all claimed). ADVANTAGE - The electrochemical sensor ensures fast detection with high sensitivity; improves the detection signal intensity in comparison with the other electrochemical detecting techniques. The method ensures convenient operation and adopts conveniently controllable parameters with respect to other optical detection methods, requires simpler devices and utilizes low cost raw materials. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the electrochemical sensor, comprising: (i) taking glassy carbon electrode with alumina polishing powder, and ultrasonically cleaning in Milli-Q water (RTM: Deionized water); (ii) mixing natural graphite (0.5-2 g), sodium nitrate (0.5-2 g) and concentrated sulfuric acid (40-60 ml); magnetically stirring in an ice bath at 0 degrees C for 3-5 hours, and then slowly adding potassium permanganate (5-7 g) after removing from the ice bath, stirring under the natural condition of 30-40 degrees C for 1-3 hours, slowly adding water (80-100 ml) and stirring in a water bath at 90-100 degrees C for 10-20 minutes, adding water (200-300 ml) and hydrogen peroxide (10-30 ml), and then centrifugally washing the liquid with hydrochloric acid and water, drying at 40-60 degrees C for 24-48 hours to obtain the graphite oxide; (iii) dispersing graphite oxide (0.05-0.2 g) in water (50-200 ml), ultrasonically peeling graphite oxide, adding 80% of hydrazine hydrate (1-4 ml) when pale yellow colloid is formed, boiling and refluxing in a water bath at 100 degrees C for 16-30 hours to produce black precipitate, vacuum filtering and drying to obtain reduced state graphene powder; (iv) reduced graphene obtained in the step 2 into the Milli-Q water (RTM: Deionized water), where the reduced state graphene content is 0.5-2g/l, ultrasonically oscillating for 20-40 minutes to obtain black uniformly dispersed reduced graphene suspension; and (v) carrying out drop coating of the glassy carbon electrode surface obtained in the step (i) with the graphene suspension (1-4 mu l), drying at room temperature, volatilizing the solvent to obtain the glassy carbon electrode as the carrier, and loading graphene as 50-60 mu g/cm2 of the carrier as the identification element.