A novel electrochemical sensing platform for anions based on conducting polymer film modified electrodes integrated on paper-based chips

In this paper, conducting polymer film modified electrodes were applied to fabricate paper-based chips (PCs), and different concentrations of chloride ions (Cl−) in water can be selectively detected based on the potential response towards Cl−. The three-electrode system was screen-printed on paper and the polypyrrole (PPy) film doped with Cl− was electrochemically polymerized on working electrodes through cyclic voltammetry in aqueous solution. Open circuit potential-time method was used to measure the potential response. Based on such PCs, Cl− can be selectively detected in the range of 10−7–10−2 M. Moreover, such PCs were utilized for Cl− analysis in real water samples and resulted in good results with recoveries between 113% and 124%. Besides, following the strategy we also employed this method to detect F− in water to demonstrate its general applicability. In view of its novelty, simplicity, sensitivity and low price, such PCs will potentially be utilized for the monitoring of anions in the environment, and our method made a start for the application of CMEs to PCs to design electrochemical sensors.