Hierarchical and hybrid RGO/ZIF-8 nanocomposite as electrochemical sensor for ultrasensitive determination of dopamine

A hierarchical and hybrid nanocomposite of reduced graphene oxide/zeolitic imidazolate framework-8 (RGO/ ZIF-8) has been successfully fabricated by the RGO as template for the in situ growth of ZIF-8. The morphology and structure of the resulted RGO/ZIF-8 nanocomposite were characterized by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was demonstrated that ZIF-8 nanoparticles anchored and grew well on the surfaces of RGO. The electrocatalytic activity of the RGO/ZIF-8 towards the dopamine (DA) was investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results demonstrated the fabricated RGO/ZIF-8 sensor exhibited high sensitivity for the determination of DA, owing to the synergistic effect from highly electrical conductivity of RGO and porosity of ZIF-8. Under the optimal conditions, the linear response range for DA was from 1.0 x 10(-7) to 1.0 x 10(-4) mol L-1 and the detection limit of DA was estimated to be as low as 3 x 10(-8) a mol L-1. Moreover, the prepared electrochemical sensor also showed excellent selectivity for DA detection in the presence of ascorbic acid (AA) and prospective results in real samples detection.