Pulstrodes: Triple pulse control of potentiometric sensors
Pulstrodes: Triple pulse control of potentiometric sensors
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DOI：
10.1021/ja047728q
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发表时间：
2004-09-01
影响因子：
15
通讯作者：
Bakker, E
中科院分区：
文献类型：
--
作者：
Makarychev-Mikhailov, S;Shvarev, A;Bakker, E
基于掺杂化学选择性主体分子的疏水材料的离子选择性电极膜是一种有吸引力的传感技术，但通常受到能斯特方程给出的有限灵敏度的影响，并且直接依赖参比电极电势，这使得小型化变得困难。这些基本问题在这里通过将多脉冲电化学激发信号施加到缺乏离子交换特性的离子选择性膜上来解决。电流脉冲负责在膜方向上产生离子通量，从而产生源自膜表面耗尽过程的可重复的超能斯特响应斜率。在此脉冲之后，还可以在零电流下测量膜，从而在较低浓度下给出超能斯特响应区域。从后续脉冲获得的差电势给出的灵敏度比根据能斯特方程预测的灵敏度高约 10 倍。
Ion-selective electrode membranes based on hydrophobic materials doped with chemically selective host molecules are an attractive sensing technology but normally suffer from a limited sensitivity, given by the Nernst equation, and a direct reliance on the reference electrode potential, which makes miniaturization difficult. These fundamental problems are addressed here by imposing a multipulse electrochemical excitation signal onto ion-selective membranes that lack ion-exchange properties. Current pulses are responsible for the generation of ion fluxes in the direction of the membrane, which give reproducible super-Nernstian response slopes that originate from depletion processes at the membrane surface. Membranes may also be measured at zero current after this pulse, giving super-Nernstian response regions at lower concentrations. Difference potentials obtained from subsequent pulses give about 10-fold higher sensitivities than predicted on the basis of the Nernst equation.