Voltammetric Heparin-Selective Electrode Based on Thin Liquid Membrane with Conducting Polymer-Modified Solid Support
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- 作者：Jidong Guo ; Shigeru Amemiya
- 刊名：Analytical Chemistry
- 出版年：2006
- 出版时间：October 1, 2006
- 年：2006
- 卷：78
- 期：19
- 页码：6893 - 6902
- 全文大小：238K
- 年卷期：v.78,no.19(October 1, 2006)
- ISSN：1520-6882
文摘
A novel, solid-supported voltammetric ion-selective electrode to detect anticoagulant/antithrombotic heparin atpolarizable poly(vinyl chloride) (PVC) membrane/waterinterfaces was developed. An ~3-4.5-
m-thick PVCmembrane plasticized with 2-nitrophenyl octyl ether wassupported on a gold electrode modified with a poly(3-octylthiophene) (POT) film as an ion-to-electron transducer. Charge transport through the PVC-covered POTfilm is electrochemically reversible, as demonstrated bycyclic voltammetry with nonpolarizable membrane/waterinterfaces. In addition to the fast charge transport, adequate redox capacity of the POT film and a small ohmicpotential drop in the thin PVC membrane enable iontransfer voltammetry at polarizable macroscopic membrane/water interfaces in a standard three-electrode cell.Reversible ClO4- transfer at the interfaces coupled withoxidation of a neutral POT film was examined by cyclicvoltammetry to determine the distribution of the appliedpotential to the two polarizable interfaces by convolutiontechnique. Interfacial adsorption and desorption of heparin facilitated by octadecyltrimethylammonium werestudied also by cyclic voltammetry and convolution technique to demonstrate that the processes are electrochemically irreversible. Stripping voltammetry based on theinterfacial processes gives a low detection limit of 0.005unit/mL heparin in a saline solution, which is slightlylower than the detection limit of most sensitive heparinsensors reported so far (0.01 unit/mL).
m-thick PVCmembrane plasticized with 2-nitrophenyl octyl ether wassupported on a gold electrode modified with a poly(3-octylthiophene) (POT) film as an ion-to-electron transducer. Charge transport through the PVC-covered POTfilm is electrochemically reversible, as demonstrated bycyclic voltammetry with nonpolarizable membrane/waterinterfaces. In addition to the fast charge transport, adequate redox capacity of the POT film and a small ohmicpotential drop in the thin PVC membrane enable iontransfer voltammetry at polarizable macroscopic membrane/water interfaces in a standard three-electrode cell.Reversible ClO4- transfer at the interfaces coupled withoxidation of a neutral POT film was examined by cyclicvoltammetry to determine the distribution of the appliedpotential to the two polarizable interfaces by convolutiontechnique. Interfacial adsorption and desorption of heparin facilitated by octadecyltrimethylammonium werestudied also by cyclic voltammetry and convolution technique to demonstrate that the processes are electrochemically irreversible. Stripping voltammetry based on theinterfacial processes gives a low detection limit of 0.005unit/mL heparin in a saline solution, which is slightlylower than the detection limit of most sensitive heparinsensors reported so far (0.01 unit/mL).