A carbon paste electrode impregnated with Cd2+ imprinted polymer as a new and high selective electrochemical sensor for determination of ultra-trace Cd2+ in water samples

A carbon paste electrode (CP) impregnated with Cd2+ ion imprinted polymer (IIP) was prepared and used for differential pulse voltammetry determination of Cd2+ in real samples. The IIP was prepared by using vinyl pyridine and quinaldic acid as functional monomer and complexing agent, respectively. Voltammetric response of the IIP–CP was considerably higher than that of the electrode modified with the non-imprinted polymer (NIP–CP), indicating properly functioning of the recognition sites of the IIP. Compared to the previously developed cadmium sensors, this sensor showed considerably better resistance against potential interfering agents such as Cu2+, Hg2+ and Pb2+. This sensor showed linear range of 1.0 × 10−9–5.0 × 10−7 M and detection limit of 5.2 × 10−10 M (S/N = 3).

► A new formulation for the preparation of high selective Cd2+ imprinted polymer.
► Cd2+ imprinted polymer as a new electrode modifying agent.
► Ultra-trace cadmium detection limit and higher selectivity compared to the previously reported Cd2+ voltammetric sensors.