Electrochemical Sensor Based on Magnetic Molecularly Imprinted Polymer and Graphene-UiO-66 Composite Modified Screen-printed Electrode for Cannabidiol Detection
Xiaosheng Tang, Yong Gu, Ping Tang, Liangliang Liu
Abstract
Cannabidiol (CBD) is a critical compound in Cannabis sativa L., having pharmacological effects in treating chronic diseases. To enrich detection methods for Cannabis sativa L and related components, we developed an electrochemical sensor to detect CBD. In this research, graphene-UiO-66 composites (Gr-UiO-66) were modified on the screen-printed electrode (SPE) together with magnetic molecularly imprinted polymer (mag-MIP), resulting in a modified sensor marked as mag-MIP/Gr-UiO-66/SPE. The prepared Gr-UiO-66 and mag-MIP were characterized by electron microscope, energy dispersive spectroscopy (EDS), and X-ray powder diffraction (XRD) to confirm the morphology and structure. The fabrication conditions and analytical parameters concerning the composition of modifiers, sequence, concentration, pH, and scan rate were investigated. Under the optimized conditions, the mag-MIP/Gr-UiO-66/SPE exhibited an enhanced electrochemical signal than that in bare electrode, the linear detection from 5 μmol L -1 to 100 μmol L -1 (r 2 = 0.997), and practicability in real samples. Based on these findings, the utilization of Gr, MOFs, and MIP showed advantages in the fabrication of electrochemical sensors. The proposed mag-MIP/Gr-UiO-66/SPE had the potential to detect natural active compounds in foods, pharmaceutical, cosmetic and health care industries.