RESUMEN
In this study, a nanocomposite was synthesized via the formation of silver nanoparticles on fumed silica (FS@Ag) to prepare an electrochemical sensor for the determination of carbendazim (CBZ), a common pesticide. The electrochemical sensor was designed by the combination of the carbon paste electrode (CPE) with the FS@Ag nanocomposite. Based on the electrochemical sensor prepared here, a voltammetric method was developed for the determination of CBZ in water and food samples. Characterization of the nanocomposite was conducted by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analyses. Modified electrodes were also electrochemically characterized via cyclic voltammetry and electrochemical impedance spectroscopy analyses. The FS@Ag showed electrocatalytic activity on the electrochemical oxidation of CBZ via increasing the peak currents tremendously. With the proposed method, a very low limit of detection (9.4 × 10-10 M) and a wide linear range (5.0 × 10-8 M - 3.0 × 10-6 M) were obtained for CBZ. The slope of the calibration line obtained with CPE/15FS@Ag was 194-times higher than that of bare CPE, indicating the high sensitivity of the electrochemical sensor. The performance of the electrochemical sensor has been investigated in real samples such as river water, tomato juice, orange juice, and apple juice samples. The results reveal that the electrochemical sensor prepared here can be used as an alternative to current analytical methods used for the quantification of CBZ.