A novel composite of reduced graphene oxide and molecularly imprinted polymer for electrochemical sensing 4-nitrophenol

A novel composite of reduced graphene oxide and molecularly imprinted polymer (RGO-MIP) was prepared using free radical polymerization and used as a recognition element in the construction of an electrochemical sensor for 4-nitrophenol (4-NP). RGO was achieved through the incomplete reduction of graphene oxide, and then 4-NP molecules were adsorbed at RGO surface due to their good affinity based on their hydrogen and π-π bonding interaction. Subsequently, selective copolymerization of methacrylic acid and ethylene glycol dimethacrylate was further carried out at RGO surface to prepare RGO-MIP. The properties of RGO-MIP sensor for 4-NP, such as special binding, response time, and recognition ability were investigated in detail. The results demonstrated that the RGO-MIP sensor not only possessed a short response time, but also a good selectivity and binding capacity for 4-NP, which enabled the RGO-MIP sensor with higher current response than that of non-imprinted polymer, traditional MIP and RGO. The RGO-MIP sensor had a wide linear range over 4-NP concentration from 0.01 to 100.0 μM with a detection limit of 0.005 μM. Furthermore, the RGO-MIP sensor not only exhibited good stability with adequate reproducibility and accuracy, but also demonstrated efficiency in the detection of 4-NP in water samples.