Choline-sensing carbon paste electrode containing polyaniline (pani)–silicon dioxide composite-modified choline oxidase

Abstract

In this study, a novel carbon paste electrode (CPE) was prepared using the salt form of polyaniline (pani)–silicon dioxide composite that is sensitive to choline. Choline oxidase (ChO) enzyme was immobilized to modified carbon paste electrode (MCPE) by cross-linking with glutaraldehyde. Determination of choline was carried out by the oxidation of enzymatically produced H₂O₂ at 0.4 V vs. Ag/AgCl. The effects of pH and temperature were investigated, and the optimum parameters were found to be 6.0 and 60°C, respectively. The linear working range of the electrode was 5.0 × 10⁻⁷–1.0 × 10⁻⁵ M, R^{2 =} 0.922. The storage stability and operation stability of the enzyme electrode were also studied.

Keywords::

• biosensor
• carbon paste
• choline
• choline oxidase
• Polyaniline (Pani)
• Polyaniline (pani)–silicon dioxide composite

Declaration of interest

The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.