Composite Polyacrylate-Poly(3,4- ethylenedioxythiophene) Membranes for Improved All-Solid-State Ion-Selective Sensors

详细信息    查看全文

• 作者：Anna Rzewuska ; Marcin Wojciechowski ; Ewa Bulska ; Elizabeth A.H. Hall ; Krzysztof Maksymiuk ; Agata Michalska
• 刊名：Analytical Chemistry
• 出版年：2008
• 出版时间：January 1, 2008
• 年：2008
• 卷：80
• 期：1
• 页码：321 - 327
• 全文大小：123K
• 年卷期：v.80,no.1(January 1, 2008)
• ISSN：1520-6882

文摘

A novel type of self-plasticizing polyacrylate-based membrane was developed for all-solid-state ion-selective potentiometric electrodes. The membrane composition contains a conducting polymer (CP): poly(3,4-ethylenedioxythiophene) end capped with methacrylate groups,chemically grafted with the membrane during the photopolymerization step. This composition results in ion-selective membranes with the following advantages: lowerelectrical resistance compared to the CP-free membrane,facile ion-to-electron transduction between the membraneand the electrode support, controlled low activity ofanalyte ions, and high concentration of interferent ions(incorporated with the CP) within the membrane, potentially resulting in improved analytical parameters. Ca²⁺-and K⁺-selective membranes were chosen as modelsystems to study the effect of pretreatment and CP contenton the potentiometric sensor's characteristics. For Ca²⁺sensors, reproducible and stable Nernstian characteristicswere obtained within the range from 0.1 to 10^-9 M CaCl_2,without a time-consuming preconditioning step. For K⁺-selective sensors, the influence on Nernstian responserange was observed for varying KCl concentrations in theconditioning solution, with the lowest detection limitfound close to 10^-8 M KCl. Mass spectrometry coupledwith laser ablation studies of the membranes revealed thatin this case the detection limit is not related to primaryion content in the membrane contacting a sample solution, but is affected by interfering ion concentration closeto the membrane surface.