Wei H, Wang T, Li S F
Department of Chemistry, National University of Singapore, Republic of Singapore.
Electrophoresis. 1997 Oct;18(11):2024-9. doi: 10.1002/elps.1150181124.
A new approach to detect underivatized carbohydrates in capillary zone electrophoresis (CZE) with a bienzyme electrode is described. The bienzyme electrode is based on immobilization of two enzymes, glucose oxidase and amyloglucosidase, on a platinum microelectrode. Maltose and glucose were used as substrates to establish the method and study its feasibility. Using this electrode, underivatized glucose and maltose were determined after separation in 60 mM borate buffer (pH 9.3) by CZE. A liquid junction, between the surface of the bienzyme electrode and the outlet of the separation capillary, was used to lower the pH of the eluting separation borate buffer so that the immobilized enzymes could maintain high activities. The detection limits were 0.17 mM for maltose and 0.35 mM for glucose. The effects of borate ion and pH on the responses of the bienzyme electrode to maltose and glucose are discussed. The bienzyme electrode did not show any decay in responses to maltose or glucose during one week of continuous operation.
描述了一种使用双酶电极在毛细管区带电泳（CZE）中检测未衍生化碳水化合物的新方法。该双酶电极基于将葡萄糖氧化酶和淀粉葡萄糖苷酶两种酶固定在铂微电极上。以麦芽糖和葡萄糖作为底物来建立该方法并研究其可行性。使用该电极，在60 mM硼酸盐缓冲液（pH 9.3）中通过CZE分离后，测定未衍生化的葡萄糖和麦芽糖。在双酶电极表面与分离毛细管出口之间使用液接界来降低洗脱分离硼酸盐缓冲液的pH值，以便固定化酶能够保持高活性。麦芽糖的检测限为0.17 mM，葡萄糖的检测限为0.35 mM。讨论了硼酸根离子和pH对双酶电极对麦芽糖和葡萄糖响应的影响。在连续运行一周期间，双酶电极对麦芽糖或葡萄糖的响应未显示任何衰减。
