MnO@C composites derived from MOFs coated with reduced graphene oxide for simultaneous detection of catechol and hydroquinone

In this work, manganese-based metal-organic frameworks (MnBDC) were synthesized by solvothermal method and physically mixed with pre-prepared graphene oxide (GO) to obtain GO/MnBDC, which were calcined to give MnO@C composite coated with reduced graphene oxide (rGO) marked as rGO/MnO@C. The materials were characterized by SEM, XRD, FTIR and XPS. Based on this composite, a novel sensor was constructed on a glassy carbon substrate, which exhibited good electrocatalytic activities to the redox reactions of catechol (CC) and hydroquinone (HQ), enabling simultaneous detection of both analytes. Under optimized conditions, the electrochemical sensor demonstrated a linear range of 0.50–90.00 μM for both CC and HQ detection, with respective detection limits of 0.05 μM and 0.03 μM. Moreover, the sensor exhibited excellent sensitivity, selectivity and accuracy for detecting CC and HQ simultaneous in real samples.