Sensitive electrochemical analysis of carbendazim as a benzimidazol fungicide on a nano-structured modified electrode

Carbendazim, a powerful antifungal compound, can interfere in the pathogen formation during mitosis leading to bacteria destruction. The fungicidal activity of carbendazim against moulds, rots and blight has been established for more than four decades. Its protecting role against apple scab, powdery mildew was confirmed which leading to citrus fruits decay [1]. Notably, in spite of their good antifungal effect, accumulation of fungicides in the environment due to their long lifetime, have been the international community's concern. Serious health problem may be raised ofindiscriminate use of pesticides in agriculture and so increasing the pesticide residue in fruits crops, such as various juice or edible oil that are routinely used in daily life [2]. Thus, an efficientquantificational technique for the pesticide residue analysis in agro-processing products is needed. Various analytical methods have been employed for carbendazim analysis such as highperformance liquid chromatography (HPLC) [3], UV–visible spectrometry [4], massspectrometry [5], voltammetry [6] and surface enhance Raman scattering [7] have been developed for the detection of carbendazim in divers environmental matrices. In the presencestudy, a nano-structured modified electrode using carbon nanoparticles (CNPs) composite wasfabricated as a sensitive electrochemical sensor for carbendazim. Preparation of the Modified GCE:Before modification, the GCE was polished with 0.05 μm alumina slurry on a polishing cloth, rinsed thoroughly with water and sonicated in water for 5 min.The modifier suspension was prepared in deionized water under ultrasonic agitation for 30 min. A desired volume (1μL in optimum value) of the suspension was cast on the pretreated GCEsurface and dried in an oven at 50 0C. Results and discussion: here the modification procedure improved colloidal dispersion of CNPsin water, affording uniform and stable thin film for altering the surface properties of the working electrode. The electrochemical behavior of carbendazim at the bare and modified electrode was investigated. The results indicated that compared to bare electrode, the prepared modifiedelectrode significantly enhanced the oxidation peak current of carbendazim. Experimental 555 parameters, parameters, such as scan rate, pH, accumulation conditions and amount of modifier used on theGCE surface were optimized by monitoring the cyclic, differential pulse and square wave voltammograms toward carbendazim. Under the optimal conditions, the modified electrode showed a wide linear response to the concentration of carbendazim in the range of 0.04-1μM.The modified electrode showed high sensitivity, long-term stability and significant voltammetric reproducibility in response to carbendazim. These excellent properties make the prepared sensor suitable for the accurate determination of trace amounts of carbendazim for analytical studies inagriculture and toxicology in environmental studies. In conclusion, in this study, the CNP composite has been applied to prepare a new sensitiveelectrochemical sensor. The modified electrode has remarkable electrochemical advantages, suchas antifouling behavior, good reproducibility and acceptable repeatability. Therefore, we believe that this sensor has potential to be used for an accurate determination of carbendazim.