Electroactive CuO nanocubes engineered electrochemical sensor for HS detection.

An electrochemical sensor was proposed for the detection of hydrogen sulfide (HS) at room temperature, by using electroactive CuO nanocubes (NCs) as an electrochemical beacon. Electroactive CuO NCs were synthesized on the surface of reduced graphene oxide (rGO)/FeO nanosheets (NSs) due to the good electronic conductivity and well-responded magnetic responses. The fabricated rGO/FeO/CuO NSs not only showed electrochemical oxidization peak at -0.1 V from CuO NCs, and could be served as sensitive electrochemical beacon for the simple modification on magnetic electrodes in the applications. The unique redox reaction between CuO NCs and HS enabled the transformation of CuO NCs to CuS 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 HS detection.