Molybdenum Trioxide Dihydrate-Graphene Composite for Electrochemical Detection of Thiourea Molecule

A novel electrochemical sensing platform was constructed based on a facile self-assembly procedure synthetic laminar molybdenum trioxide dihydrate (MoO3.2H₂O)-graphene composite. Field emission scanning electron microscopy (FESEM), X-ray spectroscopy, X-ray diffraction (XRD) and Raman spectroscopy were employed to characterize the morphology and composition of the MoO3.2H₂O-graphene composite. As a model molecule, thiourea was utilized to investigate the electrochemical behaviors of the MoO3.2H₂O-graphene composite modified glass carbon electrode. The results show that the composite modified electrode has higher electron transfer rate than that of graphene modified electrode and bare glass carbon electrode meanwhile the peak currents of it has a good linear relationship with thiourea concentrations in the range of 2.40×10-3-19.3×10-3M (R=0.998) with detection limit of 4.99μM (S/N=3). This novel electrochemical sensor exhibits a higher absorption capacity (3.87×10-8mol/cm²), a good reproducibility (1.41% relative standard deviation (RSD)), excellent anti-interference and a high stability. These excellent electrochemical properties of the MoO3.2H₂O-graphene composite are attributed to the loose and porous structure and the synergistic effects between graphene and MoO3.2H₂O, which make this composite material hold great potential applications for electrochemical sensor.