MOF / juniper leaf biochar hybrid for ultrasensitive and selective electrochemical detection of carbendazim in food

In this work, we present a novel electrochemical sensor for carbendazim (CBZ) detection, based on an eco-friendly biochar (BC) derived from juniper leaves modified with UiO-66-NH 2 metal-organic framework (MOF). Moreover, the electrochemical activation of the UiO-66-NH2@BC composite, via cyclic voltammetry (CV), improves the number of active sites and improves the electrocatalytic properties and sensitivity for CBZ detection. The structural and elemental characteristics of the synthesized materials were comprehensively analyzed by Scanning Electron Microscopy coupled with Energy-Dispersive X-ray spectroscopy (SE-EDX), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS), confirming the successful integration and preservation of both phases. Differential Pulse Voltammetry (DPV) demonstrated two linear concentration ranges (7.5 × 10 −9 - 2.5 × 10 −7 M and 2.5 × 10 −7 - 1 × 10 −6 M), with a detection limit of 4.9 × 10 −9 M, and high sensitivity (4.31 × 10 8 A M −1 cm −2 ). To verify the performance and applicability of our sensor in a real environment, we tested it on apple pulp, tomato pulp, and tap water, which gave acceptable recovery rates of 88 % to 114 % , demonstrating its ability to work in complex environments.