Studies on fabrication and application of arsenic electrochemical sensors based on titanium dioxide nanoparticle modified gold strip electrodes

Abstract

A sensitive electrochemical sensor for the determination of arsenic(III) based on a titanium dioxide (TiO₂) nanoparticle modified gold strip electrode (GSE) was developed. The gold strip electrode was prepared by a seeded growth method using polyethylene terephthalate (PET) films as the template. This GSE can provide an excellent electrochemical performance comparable to commercial gold disk electrodes, and possessed better flexibility and size controllability, as well as a larger effective surface area. A disposable thin-film electrochemical sensor was fabricated by a chemical modification method based on the gold strip electrode coating with TiO₂ nanoparticles. The resulting sensor showed a sensitive electrochemical response toward the oxidation of As(III) in hydrochloric acid (HCl) medium. Under optimized working conditions, the oxidation peak current of As(III) obtained by linear sweep voltammetry (LSV) linearly increased with its concentration in the range of 10–80 μg L⁻¹. The arsenic sensor also showed good stability and reproducibility, and was successfully applied to the detection of As(III) in blood samples.