Disposable electrochemical sensor based on ion imprinted polymeric receptor for Cd(II) ion monitoring in waters

Cadmium is a highly toxic heavy metal, even at low concentrations. Moreover, it bio-accumulates with a long biological half-life producing a wide variety of acute and chronic effects like cancer in humans. Therefore, there is significant interest in providing a portable and user-friendly sensor for heavy metal detection. A highly sen-sitive and selective electrochemical sensor for Cd(II) determination was developed as an alternative. The Cd (II) receptors were integrated into the sensor using an ion-imprinted polymer film (IIPs film). Accordingly, 4-amino-phenylacetic acid (4-APA) was electropolymerised in the presence of Cd(II) ions as a template using cyclic voltammetry (CV) on screen-printed carbon electrodes (SPCEs). Imprinted cavities were obtained after the alkaline elution of ions. Sensor characterisation was performed using SEM, ATR-FTIR and electrochemical methods, such as cyclic voltammetry (CV) and electrochemical Impedance Spectroscopy (EIS), and compared to control experiments (not imprinted polymeric film, NIP film). Analytical performances of the IIP sensor revealed a sensitivity 5-order of magnitude higher than the NIP response in a concentration range from 10 to 1200 nM of Cd (II). This technology can potentially be applied for water quality control and monitoring of heavy metals.