Simultaneous electrochemical determination of carbendazim and thiabendazole pesticides based on UiO-66(Zr)-NH-OC-MWCNT 3D coated glassy carbon electrode

The work reported herein describes the synthesis of a 3D material UiO-66(Zr)-NH-OC-MWCNT by combining a synthesized metal–organic framework UiO-66(Zr)-NH₂ and a carboxy functionalized multi-walled carbon nanotube MWCNT-COOH via an amide linkage and demonstrated its application for simultaneous electrochemical determination of two benzimidazole fungicides-carbendazim and thiabendazole. Different analytical techniques like Fourier transform infrared spectroscopy, X-ray diffraction analysis, Brunauer–Emmett–Teller analysis, and Field emission scanning electron microscopy were employed to characterize all the synthesized materials. The electrochemical characterization of the fabricated electrode was carried out using cyclic voltammetry and electrochemical impedance spectroscopy. Cyclic voltammetry and differential pulse voltammetry techniques have been used for the electroanalysis of carbendazim and thiabendazole. A limit of detection of 0.077 µM and 0.557 µM, respectively, have been obtained in the calibration range of 0.1 to 40 µM for carbendazim and 1 to 40 µM for thiabendazole, after optimization of several parameters which are susceptible to the sensitivity and selectivity of the developed sensor. Furthermore, with satisfactory results from the study of interferences, repeatability, and reproducibility, the proposed electrochemical sensor was successfully applied for analysis of carbendazim and thiabendazole in real samples.