An electrochemical sensor for Cd2+ based on the inducing adsorption ability of I−

Herein, an electrochemical sensor for sensitive and simple determination of Cd2+ was fabricated based on the excellent properties of acetylene black (AB) and strong inducing adsorption ability of I−. In pH 3.6 HAc–NaAc buffer containing 5.0 × 10−3 mol L−1 I−, Cd2+ was induced to accumulate at AB paste electrode surface under the inducing adsorption of I−, and then reduced to Cd at −1.10 V. During the following potential sweep from −1.10 to −0.40 V, reduced Cd was oxidized, resulting in a sensitive and well-shaped stripping peak at −0.83 V. Based on this, a new electrochemical method was developed for Cd2+ analysis. The linear range is found to be 5.0 × 10−8 to 2.0 × 10−6 mol L−1, and the detection limit is 2.0 × 10−8 mol L−1. Finally, this sensor was successfully used to detect Cd2+ in water samples.