Electrochemical behavior of thionine at titanate nanotubes-based modified electrode: A sensing platform for the detection of trichloroacetic acid

Titanate nanotubes (TNTs) have some unique and seductive properties, such as good biocompatibility, negative charge after treating with weak bases and supply of special reaction vessel for analyte due to their hydroxyls and multilayered structures. Herein, titanate nanotubes were firstly self-assembled on the chitosan (CHIT) membrane modified electrode. Then thionine, as a model electrochemical probe, was firmly immobilized onto the titanate nanotubes (TNTs)-based sensing interface. This strategy provided a new route to immobilize the redox mediator onto the sensing interface. Based on which, trichloroacetic acid (TCA) was found to be able to accelerate the electron transmission rate and improve the electrochemical behavior of thionine. Therefore, a wide linear range for the detection of TCA was estimated to be from 6 μM to 1.5 mM with high sensitivity and good selectivity.