Gold electrode functionalized with catalase for impedimetric detection of nitrite
Résumé
The principle of the developed biosensor includes the following: Catalase catalyzed the breakdown of H2O2 into H2O and O2. Nitrite was selected as an inhibitor of catalase. Faradaic Electrochemical Impedance Spectroscopy (EIS) has been used in our work as a tool for the characterization of a new nitrite biosensor for environmental applications based on the immobilization of catalase on gold electrode. Under optimal conditions, i.e., buffer capacity corresponding to 3 mM phosphate buffer, the catalase enzyme biomembrane shows a high sensitivity to nitrite inhibition. In both cases, the responses of these biosensors based on nitrite additions are good with a detection limit around 8 × 10−11 M.