Electroanalytical sensing of trichloroacetic acid based on activated self-supported porous silver wire prepared by voltammetric etching with trichloroacetic acid as etchant

Abstract

• Self-supporting highly active porous silver electrodes fabricated by a simple voltammetric etching method. • Increase in electrode active sites by creating a molecular imprinting-like effect during preparation. • Interfacial contact failure caused by excessive dissolution is blocked by the embedding of TCA molecules in micro-nanostructures. • The electrode exhibits good electrocatalytic activity and enables the electrochemical detection of TCA. A novel approach has been designed using trichloroacetic acid as etching molecule to prepare a highly activated self-supporting porous silver electrode for electrochemical detection of trichloroacetic acid. By analyzing the molecular structure, it contains three carbon-chlorine bonds, which can be controlled to form and break the silver-chlorine bonds. It is speculated that trichloroacetic acid molecules can be embed into micro-nano structures through Ag-Cl 3 CCOOH bonding, thus blocking the interface contact failure caused by excessive dissolution of AgCl and displaying the gate effect of imprinted trichloroacetic acid molecules. The performance of the electrochemical sensor constructed by trichloroacetic acid etching are significantly improved. Under the optimal conditions, the determination of TCA was performed with a linear range of 0.05 – 313.20 μmol·L −1 and a detection limit of 0.035 μmol·L −1 . The electrochemical sensor has good reproducibility and stability with relative standard deviations of 4.5% and 3%, respectively, and still achieve 95% of the initial current value after two weeks.