Development of A New Electrochemical Sensor based on Zr-MOF/MIP for Sensitive Diclofenac Determination

Abstract

In this study, a new molecularly imprinted polymer with nanoporous material of zirconium metal-organic frameworks (Zr-MOF/MIP) for diclofenac (DFC) measurement is presented. The Zr-MOF/MIP was prepared by electropolymerization method, the Zr-MOFs were used to increase electrode surface and the DFC and para- aminobenzoic acid (pABA) were used as template and functional monomer, respectively. Zr--MOFs was characterized by using X-ray powder diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The electrochemical performance was investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Sensor response was evaluated by comparing the electrochemical response of Zr-MOF/MIP, with that of non- Imprinted polymer (NIP), in a 2.0 mM potassium ferrocyanide solution containing 0.2 mM sodium sulfate as probe solution. Measurements were carried out in the potential range of -0.6 to +1.0 V with scan rate of 50 mV/s. The calibration curve of diclofenac was linear in the concentration range of 6.5 μM to 1.5×10⁺³ μM. Detection limit was obtained 0.1 μM and relative standard deviation of several (n=7) replicate measurements for 1.0 mM DFC concentration has obtained 1.8%. Furthermore, favorable sensitivity, selectivity, good reproducibility and long-term stability, was obtained in the experiment and the proposed electrode was applied for the determination of DFC in pharmaceutical commercial sample with satisfactory results.