title: Determination of total bile acid levels using a thick-film screen-printed Ir/C sensor for the detection of liver disease.
abstract: An electrochemical sensor, based on thick-film screen-printed Ir/C working and counter electrodes, was developed for the detection of total bile acid concentration in a physiological fluid for potential patient management in patients with liver disease. Current electrochemical methods of detecting total bile acid levels involve the use of potentials greater than +0.45 V, versus an Ag/AgCl reference electrode, and require a selectively permeable membrane. The proposed detection method did not require any membrane and used a potential of +0.27 V versus Ag/AgCl. This biosensor used 3-alpha-hydroxysteroid dehydrogenase (3alpha-HSD) (EC 1.1.1.50) immobilized on the thick-film screen-printed working electrode to detect the enzymatically generated NADH. The production of the NADH resulted from the reaction of the enzyme with bile acids such as sodium cholate, taurocholic and taurochenodeoxycholic acid, which could then be used to quantify the total bile acid. Constant potential measurements showed that this biosensor had good linear performance over a 0-200 microM concentration range in the phosphate buffer and the bovine serum. The sensor performance was also examined at different temperatures and pH conditions. This sensor prototype could be used for single use, disposable detection of total bile acids, extending its applicability for simple and early detection of liver disease.
authors.affiliation: Department of Chemical Engineering and the Electronics Design Center, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. brandon.bartling@case.edu
authors.forename: Brandon
authors.initials: B
authors.lastname: Bartling
authors.forename: Lu
authors.initials: L
authors.lastname: Li
authors.forename: Chung-Chiun
authors.initials: CC
authors.lastname: Liu
mesh_terms: D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific); D000818:Animals; D001647:Bile Acids and Salts / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004800:Enzymes, Immobilized; D006863:Hydrogen-Ion Concentration; D008107:Liver Diseases / Q000175:diagnosis*; D009243:NAD / Q000737:chemistry; D013696:Temperature
chemical_list: D001647:Bile Acids and Salts; D004800:Enzymes, Immobilized; D009243:NAD; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)