Electroactive Cu2O nanocubes engineered electrochemical sensor for H2S detection.

An electrochemical sensor was proposed for the detection of hydrogen sulfide (H2S) at room temperature, by using electroactive Cu2O nanocubes (NCs) as an electrochemical beacon. Electroactive Cu2O NCs were synthesized on the surface of reduced graphene oxide (rGO)/Fe3O4 nanosheets (NSs) due to the good electronic conductivity and well-responded magnetic responses. The fabricated rGO/Fe3O4/Cu2O NSs not only showed electrochemical oxidization peak at -0.1 V from Cu2O NCs, and could be served as sensitive electrochemical beacon for the simple modification on magnetic electrodes in the applications. The unique redox reaction between Cu2O NCs and H2S enabled the transformation of Cu2O NCs to Cu9S8 NCs, resulting in decreased electroxidation responses at -0.1 V. The constructed electrochemical platform had a limit of detection (LOD) of 230 pM and a detection range of 500 pM-100 μM. The simple and cheap electrochemical sensor developed in this paper showed potential application for H2S detection.