Comparison of Electrochemical Behavior of Bile Acids and Their Conjugates on the Boron-Doped Diamond Electrode
Abstract
The electrochemical behavior of bile acids (cholic and chenodeoxycholic acids) and their conjugates with taurine (taurocholic and taurochenodeoxycholic acids) and glycine (glycocholic and glycochenodeoxycholic acids) was studied using cyclic voltammetry on boron-doped diamond electrode. Specifically, the difference between the response of bile acids and their conjugates in the positive potential region was investigated in the media of acetonitrile - perchloric acid (water content 0.55 %).
All the studied substances contain a 7α hydroxyl group, and thus can undergo dehydration reaction, resulting in activation of the steroid core for electrochemical oxidation. It results in anodic irreversible signal at ca +1.2 V (vs.
Ag/AgNO3 in acetonitrile), providing a base for their electrochemical detection.