Impedimetric immunosensor for atrazine detection based on polypyrrole nanowires

Abstract

An impedưnetric immunosensor based on polypyưole (PPy) nanowires was developed and applied for atrazine (ATZ) herbicide detection. In this work, the PPy nanowires were synthesized by an electrochemical free-template method onto an interdigilaled platinum micro­electrode (IDpE). The immunosensors were prepared by immobilization of monoclonal anti- atrazine antibody (a-ATZ) onto a PPy surface using glutaraldehyde as a cross-linker. The electrodes were characterized using scanning electron microscopy (SEM), cyclic voltammetry (CV) and Founer transform infrared spectroscopy (FT-IR) techniques. The ATZ analysis is based on the immunoreaction of ATZ and a-ATZ attached on lop of the IDpE area (fingers and inter-digits space) by means of electrochemical impedance spectroscopy (EIS). Thanks to immunoreagent specificity, these sensors exhibit high selectivity and sensitivity for ATZ detection with a threshold of 10 ng/mL.