Fabrication of molecular imprinted polymer sensor for chlortetracycline based on controlled electrochemical reduction of graphene oxide

A molecular imprinted polymer (MIP) sensor was fabricated by directly eletropolymerizing monomer o-phenylenediamine in the presence of template chlortetracycline (CTC), based on controlled electrochemical reduction of graphene oxide (GO) at cathodic potentials. In comparison with GO, the reduced GO (RGO) increased the cyclic voltammetric peak currents of [Fe(CN)6]3−/[Fe(CN)6]4− redox pair by a factor of about 300%, which was influenced by the amount of used GO and the reduction time. Integrating the excellent response amplification of RGO and the special recognition of MIP, the new MIP sensor was used to detect CTC indirectly by using [Fe(CN)6]3−/[Fe(CN)6]4− redox pair as an electrochemical probe. The electrochemical performances of the sensor were evaluated with cyclic voltammetry and differential pulse voltammetry (DPV). The MIP sensor exhibited a wide-range linear correlation between the peak current variation (ΔI) of the DPV cathodic peak and the concentration of CTC in the range of 10.0-500.0 μM. The use of the RGO-based MIP sensor gave satisfactory results in the analysis of tap water and laboratory wastewater samples.