A membrane-moderated, conductimetric sensor for the detection and measurement of specific organic solutes in aqueous solutions
A membrane-moderated, conductimetric sensor for the detection and measurement of specific organic solutes in aqueous solutions
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DOI：
10.1016/s0376-7388(99)00283-5
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发表时间：
2000-03-30
影响因子：
9.5
通讯作者：
Michaels, AS
中科院分区：
文献类型：
--
作者：
Arnold, FH;Zheng, WG;Michaels, AS
描述了一种新型电导传感器，能够检测和连续监测多组分水溶液（例如全血或血浆）中特定非离子微量溶质（葡萄糖）的浓度，并提出了支持该传感器概念有效性的初步实验证据。检测基于使用葡萄糖选择性络合剂（固定在水凝胶中的硼酸），当与葡萄糖分子结合时，该络合剂会释放出移动的微离子（氢离子）。因此，离子浓度增加导致的水凝胶离子电导率的变化与环境葡萄糖浓度直接相关。为了使电导测量有意义，必须将释放的离子限制在水凝胶内，并防止测试溶液中存在的外来电解质进入。这是通过将水凝胶封装在双极性离子交换膜内来实现的，该双极性离子交换膜对离子不可渗透，但对葡萄糖和其他非离子微溶质可自由渗透。提出了络合平衡、溶质通过膜和水凝胶相传输的动力学及其对水凝胶离子电导率的影响的物理化学模型，该模型支持该传感器概念作为潜在可靠且灵敏的葡萄糖监测仪的实用性。建议将其用于监测多组分水溶液中的非离子微溶质。 (C) 2000 Elsevier Science B.V. 保留所有权利。
A novel conductimetric sensor, capable of detecting and continuously monitoring the concentration of a specific nonionic microsolute (glucose) in a multicomponent aqueous solution (e.g., whole blood or plasma) is described, and preliminary experimental evidence supporting the validity of the sensor concept is presented. Detection is based upon the use of a glucose-selective complexing agent (a boronic acid immobilized in a hydrogel) which liberates a mobile microion (hydrogen ion) when it binds a glucose molecule. The change in ionic conductivity of the hydrogel resulting from the increase in ion concentration is thus directly related to the ambient glucose concentration. Confinement of the liberated ions within the hydrogel, and prevention of entry of extraneous electrolytes present in the test solution, is necessary to make the conductimetric measurement meaningful. This is achieved by encapsulating the hydrogel within a bipolar ion exchange membrane impermeable to ions but freely permeable to glucose land other nonionic microsolutes). A physicochemical model of the complexation equilibrium, kinetics of solute transport through the membrane and hydrogel phase, and their impact upon the ionic conductivity of the hydrogel is presented, which supports the utility of this sensor concept as a potentially reliable and sensitive glucose monitor. Its generic utility for monitoring nonionic microsolutes in multicomponent aqueous solutions is suggested. (C) 2000 Elsevier Science B.V. All rights reserved.