A simple and sensitive electrochemical sensor for new neonicotinoid insecticide Paichongding in grain samples based on β-cyclodextrin-graphene modified glassy carbon electrode

A simple and sensitive sensor based on beta-cyclodextrin-graphene modified glassy carbon electrode (beta-CD-rGOIGCE) was developed for the electrochemical determination of new neonicotinoid insecticide Paichongding (IPP). In 0.1 M phosphate buffer solution, the electrode offers low reduction potential and the peak current of IPP increased significantly at beta-CD-rGO/GCE compared with bare GCE and rGO/GCE. Furthermore, low temperature is beneficial to further improve the peak current and determination sensitivity. The reduction mechanism and binding affinity were discussed. The experimental conditions that exert influence on the voltammetric determination of IPP, such as temperature, pH values and accumulation time were optimized. Besides, the interference, reproducibility and stability measurements were also evaluated. Under the optimal experimental conditions, a linear relationship between the peak current and the concentration was obtained from linear sweep voltammetry in the range from 1 to 10 mu M, 10 to 55 mu M, with the detection limit of 0.11 mu M and quantification limit of 0.37 mu M. This sensor was used successfully for IPP determination in grain samples. The results show good agreement with the HPLC method. (C) 2016 Elsevier B.V. All rights reserved.