Hybrid of dandelion-like hollow Mo2C nanospheres-graphene nanosheets as the electrode for highly sensitive electrochemical detection of dopamine

Molybdenum polydopamine hollow nanospheres were synthesized by liquid-phase reactions at room temperature and they were transformed into molybdenum carbide (Mo 2 C) when annealed at 800℃. Subsequently, they were self-assembled with graphene oxide (GO) and sprayed onto the indium tin oxide (ITO) glass. After heating at 400℃, the Mo 2 C - reduced GO/ITO (Mo 2 C - rGO/ITO) electrode was obtained and used for the detection of dopamine (DA). The results show that Mo 2 C is made up of dandelion-like hollow nanospheres with an outer and inner diameter of 500 and 200 nm, and Mo 2 C is homogeneously mixed with rGO nanosheets. Due to the synergistic effect of the excellet electrocatalytic properties of Mo 2 C and electrical conductivity of rGO, the hybrid Mo 2 C - rGO/ITO electrode shows a high sensitivity (8.30 μA·μM −1 ·cm −2 ) and a low limit of detection (LOD) (0.058 μM, S/N = 3) for DA in the range of 0–60 μM. Additionally, the electrode shows a good repeatability and stability, and it is also successfully used for the determination of DA in diluted human urine. It has a great potential for clinical applications.