Application of Bi/PEDOT composite modified electrode in high-performance Cd (II) detection sensor

Abstract

In this paper, Bismuth/poly(3,4-ethylenedioxythiophene) (Bi/PEDOT) modified electrochemical modified electrodes were prepared by electrochemical deposition method, and the electrochemical performance of the electrode was investigated using cyclic voltammetry under the optimal experimental conditions. The PEDOT polymer has high conductivity, and bismuth can form an alloy with cadmium ions. Bi/PEDOT nanocomposite materials have a larger specific surface area and more active sites, which is more conducive to absorbing more cadmium ions (Cd²⁺). The Differential pulse anodic stripping voltammetry method was used to study the electroanalytical performance of the sensor for Cd²⁺. The data show that the oxidation peak current of cadmium ions in the Bi/PEDOT modified electrode is significantly higher than that of other electrodes, due to the synergistic effect of the composite conductive materials. In the concentration range of 1 nM-40 μM, the concentration of cadmium ions shows a good linear relationship with the peak current, and the lowest detection limit is 0.33 nM. In addition, the sensor also exhibits good stability, reproducibility and very low detection limit, which can be used for rapid determination of trace cadmium ions, with a recovery rate in actual sample analysis of 101.4 %-104.0 %.