Applicability of a PEDOT coated electrode for amperometric quantification of short chain carboxylic acids
Applicability of a PEDOT coated electrode for amperometric quantification of short chain carboxylic acids
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DOI：
10.1016/j.snb.2017.08.033
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发表时间：
2018-02
影响因子：
8.4
通讯作者：
Rodrigo Fernández Feito;R. Dinsdale;A. Guwy;G. Premier
中科院分区：
文献类型：
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作者：
Rodrigo Fernández Feito;R. Dinsdale;A. Guwy;G. Premier
短链羧酸被称为挥发性脂肪酸（VFA）是生物过程的重要产物，因此，它们的测量长期以来一直是畜牧业，厌氧消化和其他生物介导过程的兴趣。虽然这样的测量是广泛的，低成本和准确的传感器在线过程监测是非常可取的，但目前还没有。研究了聚（3,4-乙烯二氧噻吩）（PEDOT）包覆电极检测VFAs浓度的适用性及其作为毛细管电泳后续分离检测器的适用性。电极进行脉冲安培操作，在其还原和氧化状态之间切换，以促进聚合物和含有VFAs的电解质溶液之间的离子交换。研究了薄膜厚度、分析物性质、脉冲持续时间和电解液浓度对电流响应的影响。乙酸钠、丙酸钠和丁酸钠浓度在0.1 ~ 10 mM范围内均具有较高的线性校准曲线（>0.998）。此外，PEDOT电极在至少一个月的时间内表现出非常稳定和精确，没有明显的薄膜变质或灵敏度损失。讨论了聚合电荷、脉动时间和电泳检测池结构的作用，并给出了提高分析背景信号的指导方针。
Short chain carboxylic acids known as volatile fatty acids (VFA) are important products of biological processes and as such, their measurement has long been of interest in animal husbandry, anaerobic digestions and other biologically mediated processes. While such measurements are widespread, a low cost and accurate sensor for online process monitoring is highly desirable, but as yet unavailable. An investigation into the suitability of Poly(3,4-ethylenedioxythiophene) (PEDOT) coated electrodes in sensing the concentrations of VFAs and their applicability as detector subsequent separation by capillary electrophoresis is presented. The electrodes were subjected to pulse amperometric operation, switching between their reduced and oxidized states to promote ion exchange between the polymer and electrolyte solutions containing the VFAs. The effects of the film thickness, properties of the analyte, the duration of the pulse and the electrolyte concentration on the current response, were studied. Linear calibration curves with high correlation coefficients (>0.998) were found within the range of concentrations 0.1–10 mM for sodium acetate, sodium propionate and sodium butyrate. Furthermore, the PEDOT electrodes were shown to be very stable and precise over at least one month and no film deterioration or loss sensitivity was in evidence. The role of the polymerization charge, the pulsation time as well as the electrophoresis detection cell configuration are discussed and guidelines to increase the analytical to background signal are given.