Dimcheva Nina, Horozova Elena, Jordanova Zinaida
Department of Physical Chemistry, University of Provdiv, Bulgaria.
Z Naturforsch C J Biosci. 2002 Sep-Oct;57(9-10):883-9. doi: 10.1515/znc-2002-9-1021.
A xanthine oxidase enzyme electrode (xanthine oxidase immobilized on electrochemically modified graphite and conveniently coated with gelatine electrode working surface) for quantitative analysis of xanthine is proposed. The detection of thus developed electrochemical system is based on the electroreduction of hydrogen peroxide generated in enzyme layer and offered L-ascorbic and uric acid reducing interference effect on the substrate determination. At a working potential -50 mV (vs. Ag/AgCl) the detection limit of 4.5 microM and the linearity of the amperometric signal up to substrate concentration of about 40 microM were found. At that working potential, the electrode is practically inert towards L-ascorbic- and uric acid present. The response time did not exceed 2 min.
提出了一种用于黄嘌呤定量分析的黄嘌呤氧化酶酶电极（将黄嘌呤氧化酶固定在电化学修饰的石墨上，并在电极工作表面方便地涂覆明胶）。如此开发的电化学系统的检测基于酶层中产生的过氧化氢的电还原，并且所提供的L-抗坏血酸和尿酸对底物测定具有还原干扰作用。在工作电位为-50 mV（相对于Ag/AgCl）时，检测限为4.5 microM，并且在底物浓度高达约40 microM时安培信号呈线性。在该工作电位下，电极对存在的L-抗坏血酸和尿酸实际上是惰性的。响应时间不超过2分钟。
