Dopamine molecularly imprinted electrochemical sensor based on graphene–chitosan composite

Abstract

A molecularly imprinted polymers (MIPs) electrochemical sensor based on graphene (GR)–chitosan (CS) composite was constructed, finally used in dopamine (DA) measurement. The MIPs-GR sensor was prepared through electrodepositing DA–GR–CS composited film on the glass carbon electrode (GCE) and then removing DA from the film via electrochemical induced elution. X-ray diffraction (XRD), attenuated total reflection infrared spectroscopy (ATR-IR), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) characterizations indicated that MIPs-GR/GCE formed an affinity film. Owing to excellent electronic properties, unique two-dimensional structure and large surface area of GR, the prepared sensor exhibited highly sensitive response to the oxidation of DA with enhanced current signal and short response time. The oxidation peak current of DPV was well-proportional to the concentration of DA in the range from 1.0×10−9 to 8.0×10−8 and 1.0×10−7 to 1.0×10−4M. The developed sensor obtained a recovery of 96.7–105.0% in the DA determination of blood serum, resulted from the specific recognition to DA against the structural analog and coexisting interferences.