Anodization of Glassy Carbon Electrodes in Oligomers of Ethylene Glycol and Their Monomethyl Ethers as a Tool for the Elimination of Protein Adsorption

Abstract

The adsorption property of bovine serum albumin (BSA) on glassy carbon (GC) electrodes anodized in HO(CH₂CH₂O)_nR (n=1-4, R=H or Me) has been evaluated by comparing cyclic voltammograms of caffeic acid before and after a treatment of the electrodes with a BSA solution. Electrodes modified with triethylene glycol and its monomethyl ether have proved to resist surface fouling due to BSA adsorption as well as to show satisfactory electrochemical performance. The reliability of the assessment was established by examining the amounts of BSA adsorbed on electrodes estimated by radioactivity measurements after a treatment with ¹²⁵I-BSA. The analytical utility of a triethylene glycol-modified GC electrode has been demonstrated by analyzing a sample containing uric acid, acetaminophen, and BSA by reversed-phase high-performance liquid chromatography with an electrochemical detector, where a commercially available packed- column, allowing the passage of proteins, namely, requiring no pretreatment of samples for the removal of proteins, was utilized.