Prepared hollow nanosphere MoO2/rGO composite for low concentration dopamine detection

Abstract

Metal oxide and graphene composite material have been a promising material for developing electrochemical sensors. In this work, we prepared graphene (rGO) doped MoO₂ hollow nanosphere composite (MoO₂/rGO) using a simple one-step solvothermal without any template.The hollow nanosphere was constructed by nanoparticles and uniformly anchored onto graphene sheets.The dopamine (DA) sensor was constructed by modifying the MoO₂/rGO composite to the glass carbon electrode (GCE) surface with a simple drop coating (MoO₂/rGO/GCE), which shows high sensitivity(101.20 μA·μM^-1·cm^-2), low detection limit (6.8 nM), high selectivity and good stability for DA. Meanwhile, the MoO₂/rGO/GCE demonstrates very little interference with dopamine determination when both Uric acid (UA) and ascorbic acid (AA) are present. The exceptional efficacy of the sensor is attributed to the MoO₂/rGO composite's unique attributes,which include a hollow structure, low charge transfer resistance, a large electrochemical active area, and an abundance of active sites. Furthermore, the MoO₂/rGO/GCE sensor demonstrates capabilities for the detection of minute dopamine levels in human serum, utilizing the standard addition method. This suggests its applicability in the realm of biomedical diagnostics.