CuS/RGO hybrid by one-pot hydrothermal method for efficient electrochemical sensing of hydrogen peroxide

In this study, a non-enzymatic hydrogen peroxide sensor was successfully fabricated on the basis of copper sulfide nanoparticles/reduced graphene oxide (CuS/RGO) electrocatalyst. Using thiourea as reducing agent and sulfur donor, CuS/RGO hybrid was synthesized through a facile one-pot hydrothermal method, where the reduction of GO and deposition of CuS nanoparticles on RGO occur simultaneously. The results confirmed that the CuS/RGO hybrid helps to prevent the aggregation of CuS nanoparticles. Electrochemical investigation showed that the as-prepared hydrogen peroxide sensor exhibited a low detection limit of 0.18 μmol/L (S/N = 3), a good reproducibility (relative standard deviation (RSD) of 4.21%), a wide linear range (from 3 to 1215 μmol/L) with a sensitivity of 216.9 μA L/mmol/cm2 under the optimal conditions. Moreover, the as-prepared sensor also showed excellent selectivity and stability for hydrogen peroxide detection. The excellent performance of CuS/RGO hybrid, especially the lower detection limit than certain enzymes and noble metal nanomaterials ever reported, makes it a promising candidate for non-enzymatic H2O2 sensors.