Enzymatic biosensor based on DropSens screen-printed electrodes for the determination of carbofuran and methyl parathion in drinking water

In this study, a new biosensor system was developed and optimized for the detection of the insecticides carbofuran and methyl parathion in drinking water using commercial DropSens electrodes. The electrode systems used were printed in ceramic, with platinum auxiliary electrode and silver reference electrode. The working electrode was modified with cobalt phthalocyanine as a redox mediator. The parameters of the working electrode, enzyme immobilization and ATChI substrate concentration were optimized. The biosensor created was used to identify carbamates and organophosphates in drinking water samples. Carbon was chosen as the main electrode, glutaraldehyde as the enzyme immobilization agent and the ideal concentration of ATChI was 100 mmol/L. The optimized biosensor showed a linearity range of 5-25 µg/L for carbofuran and 10-45 µg/L for methyl parathion. The detection values for carbofuran and methyl parathion were 0.210 µg/L and 0.292 µg/L, respectively, with quantification limits of 0.637 µg/L and 0.884 µg/L, respectively. In the tests carried out with water, the biosensor was able to recover between 9903% of the two insecticides. The results showed the effectiveness of this biosensor for detecting the insecticides carbofuran and methyl parathion.