In situ synthesis of sandwich MOFs on reduced graphene oxide for electrochemical sensing of dihydroxybenzene isomers

A novel type of sandwich MOF was successfully synthesized on reduced graphene oxide (denoted as M@Pt@M-rGO) by an in situ synthesis method. The obtained M@Pt@M-rGO possesses excellent electrochemical properties. The surface morphology and structure of M@Pt@M-rGO were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), etc. By using M@Pt@M-rGO, a novel electrochemical sensor was constructed and successfully used for the simultaneous and sensitive detection of three isomers: hydroquinone (HQ), catechol (CT) and resorcinol (RS), with wider linear ranges of concentrations of 0.05–200 μM, 0.1–160 μM and 0.4–300 μM and lower detection limits of 0.015 μM, 0.032 μM and 0.133 μM (S/N = 3) for HQ, CT and RS, respectively. Besides, the proposed electrochemical sensor showed excellent anti-interference capability, high stability, good reproducibility, and satisfactory recovery for determination of isomers in river and lake water.