胆绿素还原酶电极及电位法测定胆红素的研究

The Study of Biliverdin Reductase Electrode and the Potentiometric Determination of Bilirubin

本文研制了胆绿素还原酶电极,采用电位法测定胆红素。胆绿素还原酶以牛血清白蛋白和戊二醛固定化制成酶膜,覆盖在石墨电极上在辅酶Ⅰ存在下进行测定,铁氰离子作为电子传递介质。胆红素在空气存在下氧化为胆绿素,再以胆绿素还原酶电极进行检测。线性响应范围为1×10^(-6)-1×10^(-4)mol/L胆绿素(胆红素),酶膜寿命约60h。本法可在水溶液中测定胆红素。

A biliverdin reductase electrode is described for the potentiometric determination of bilirubin. Biliverdin reductase was immobilized with glutaric dialdehyde on bovine albumin for preparing a nuclepore enzyme membrane, The enzyme membrane was covered on a graphite electrode. The immobilized enzyme can catalyze the reduction of substrate biliverdin in the presence of eoenzyme Ⅰ. Ferrocyanide was used as the redox mediator to transfer electrons. The bilirubin was preoxidized to biliverdin with air, then detected biliverdin by using reductase electrode. The limit of detection is 1 × 10^(-6)mol/L and the response is linear up to 5 × 10^(-4)mol/L bilirubin. The enzyme electrode exhibited an optimum pH 8.5 and a lifetime of 60 hours. The results indicate that immobilized biliverdin reductase can be incorporated into a system to detect bilirubin in aqueous solution.