Electrochemical quantification of mancozeb through tungsten oxide/reduced graphene oxide nanocomposite: A potential...

The extensive use of pesticides for better yield of crops have become major human concern over the decades. Pesticides are widely used in the fields to kill weeds and pests on the vegetable and crops to improve the quality and yield of the food knowing the fact that pesticides residue in food are very lethal for human being. Amongst, the hazardous pesticides, mancozeb is widely applied in the protection of crops. Thus the quantification of mancozeb residue is of great importance. This study reports the electrochemical monitoring of mancozeb through tungsten oxide reduced graphene oxide (WO₃/rGO) nanocomposite. The engineered nanocomposite was characterized though different analytical tools such as FTIR, XRD and TEM to examine crystallinity, internal texture and the size. The FTIR result confirm the functionalities of GO and WO₃/rGO nanocomposite in finger print and functional group region. Through XRD analysis, the size of the WO₃/rGO nanocomposite was calculated as 31.6 nm. While the TEM analysis was also exploited to examine the 2D texture of GO and nanometric size of the WO₃/rGO. To ensure the conductive nature of the WO₃/rGO nanocomposite, the glassy carbon electrode was modified and exploited for cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimal conditions, the modified sensor showed exceptional response for mancozeb. The linear dynamic range was set from 0.05 to 70 μM in BRB buffer of pH 4. The LOD and LOQ for proposed method was calculated as 0.0038 and 0.0115 μM. The analytical applicability of chemically modified sensor was investigated in real matrix of different vegetable samples and the recovery values were observed in acceptable range. The electrochemical examination of present work reveals that WO₃/rGO nanocomposite can be an exceptional aspirant for the determination of mancozeb at commercial level.