Copper sulfide|reduced graphene oxide nanocomposite for detection of hydrazine and hydrogen peroxide at low potential in neutral medium

We report a hydrogen peroxide (H2O2) and hydrazine sensor based on novel copper sulfide|reduced graphene oxide (CuS|rGO) nanocomposites, which were synthesized with a facile hydrothermal method. It was discovered that the aggregation of graphene nanosheets could be reduced very significantly by the formation of CuS|rGO composites. The sensor was fabricated by simple casting of CuS|rGO aqueous suspension on glassy carbon electrode (GCE) and its performance was evaluated by cyclic voltammetry and amperometric techniques. It was found that the resulting sensor exhibited good performance toward H2O2 detection with wide linear response ranging from 1 × 10−6 to 1 × 10−3 M (R = 0.996) at -0.2 V and low detection limit of 1 × 10−7 M estimated at a signal-to-noise ratio of 3. In addition, the fabricated sensor also exhibited high sensitivity toward the detection of hydrazine with a low detection limit of 3 × 10−7 M, wide linear range from 1 × 10−6 to 1 × 10−3 M (R = 0.999) at 0.4 V. For both analytes, the sensor exhibited good reproducibility, selectivity and stability.