A disposable simultaneous electrochemical sensor array based on a molecularly imprinted film at a NH2-graphene...

A disposable simultaneous electrochemical sensor array based on a molecularly imprinted film with a screen-printed electrode (SPE) has been developed for the detection of psychotropic drugs. A molecularly imprinted film (MIF) was synthesized by electro-polymerization using methcathinone and cathinone as the templates and pyrrole (py) as the monomer. Scanning electron microscopy (SEM) was employed to characterize the surface morphology of the MIF. The conductivity of the SPE was improved by the NH2-graphene (NG). The surface feature of the modified electrode was characterized by cyclic voltammetry (CV) and an electrochemical impedance method. The proposed sensor array was tested by differential pulse voltammetry. Several important parameters controlling the performance of the molecularly imprinted sensor array were investigated and optimized. Under the optimal conditions, this multiplexed immunoassay method showed wide linear ranges over 3 orders of magnitude with the detection limits (S/N = 3) down to 3.3 and 8.9 pg mL(-1) for methcathinone and cathinone, respectively. This disposable simultaneous electrochemical sensor array was successfully employed to detect methcathinone and cathinone in practical serum samples. The disposable simultaneous strategy avoided crosstalk and the need of deoxygenation for the electrochemical sensor, thus, provided a promising potential in clinical applications.