Developing a modified bipolar electrode for selective measurement of nitrate ion based on palladium nanoparticles deposited on a cathode pole

In a bipolar electrochemistry (BPE), an isolated conductor substrate which called bipolar electrode , is placed in the electrolyte solution and an external electric field isapplied to it [1]. Also, there is no physical connection between the bipolar electrode and the power supply [2]. Here we report a modern type of sensing platform that relies on the electrodissolution of a metallic layer on a bipolar electrode (BPel). In this study, we designed a modified bipolar electrode that makes it possible to measure nitrate ion (Fig. 1). In the proposed method, the silver layer deposited on a recordable digital versatile disc (DVD-R) has the role of an anode pole of a bipolar electrode. The nitrate ion is reduced on the cathodic pole which has been modified by copper and palladium nanoparticles, and at the same time dissolution of the silver layer in the anodic pole takes place. Length of the silver layer dissolution was considered as the analytical signal. Through the BPE method, the linear range and the detection limit of nitrate were found to be 0.5 - 3500.0 μM and a detection limit of 0.16 μM respectively. Moreover, the proposed method was used to determine of nitrate ion in industrial samples and the results indicated that this modified bipolar electrode has great potential for practical applications