An enzymic method for the determination of bilirubin using an oxygen electrode

An enzymic method for the determination of bilirubin is described, based on the indirect electrochemical monitoring of bilirubin via its reaction with oxygen to biliverdin in the presence of bilirubin oxidase. Amperometric si gnals due to oxygen depletion were taken by means of an oxygen electrode in corporating an immobilized bilirubin oxidase membrane. The calibration plot shows linearity up to 2.0 x 10(-4) M. This concentration range corresponds to elevated bilirubin concentrations in adults and in newborn infants. The RSD of the method is 3.1 % (1.0 x 10(-4) M bilirubin, n = 6). The method i s interference free, fast ( < 3min) and easy to perform. The membrane retai ns almost 80 % of its initial activity after 30 successive measurements.