Enhanced molecular imprinted electrochemical sensor based on zeolitic imidazolate framework/reduced graphene oxide...

Exceptional sensitivity behavior of molecularly imprinted polymer (MIP) approach towards an electrochemical sensor application encourages combining this approach with other materials to tune their properties such as large surface area, high catalytic effect, electrical, thermal and mechanical stability for the fabrication of sensors with high sensitive performance. In the present work, highly sensitive MIP sensor was developed and successfully applied for rutin recognition. The MIP was decorated on the surface of zeolitic imidazolate framework (ZIF-8) and reduced graphene oxide (rGO) composite modified with glassy carbon electrode (GCE) to fabricate GCE/rGO/ZIF-8/MIP electrode. Spectroscopic and microscopic analyses such as XRD, FT-IR, BET and SEM were used to evaluate the composition and the morphology of the surface of GCE/rGO/ZIF-8/MIP electrode. The electrochemical characterization of electrodes was performed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Also different parameters influencing the sensitivity of GCE/rGO/ZIF-8/MIP, such as the percentage of rGO, template:monomer ratio, number of electropolymerization cycles, accumulation time and pH were optimized. Under optimal conditions, the MIP sensor shows a wide linear range and low limit of detection as well as good reproducibility, stability and selectivity, and used successfully for the determination of rutin in real solutions.