Diaminoanthraquinone polymer modified glassy carbon electrode for the voltammetric determination of imidacloprid

A simple electrochemical sensor was developed towards the widely used insecticide Imidacloprid (IMI) using a redox active polymer, poly(1,5-diaminoanthraquinone) (PDAAQ) modified glassy carbon electrode (GCE). The electro catalytic reduction of IMI was obtained using the GCE/PDAAQ electrode in phosphate buffer solution having pH 7. The irreversible reduction of IMI occurs at a potential of -1.031 V with a slight shift towards negative potential with increase in concentration of IMI. The linear range obtained is 9.98 x 10-6 to 6.6 x 10-4 M with a limit of detection 2.95 x 10-7 M. Repeatability and reproducibility of the sensor was checked and was found to be in the acceptable range with relative standard deviation less than 5%. Selectivity of the sensor was studied in presence of various metal ions and organic molecules and found that there is no significant interference. IMI analysis was done using spike recovery tests in well water and cucumber juice samples which shows that the developed sensor can be successfully applied to the trace determination of IMI in real samples.