Fluorous-Phase Ion-Selective pH Electrodes: Electrode Body and Ionophore Optimization for Measurements in the Physiological pH Range
Fluorous-Phase Ion-Selective pH Electrodes: Electrode Body and Ionophore Optimization for Measurements in the Physiological pH Range
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DOI：
10.1021/acsomega.0c00582
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发表时间：
2020-06-16
期刊：
影响因子：
4.1
通讯作者：
Buhlmann, Philippe
中科院分区：
文献类型：
--
作者：
Chen, Xin, V;Mousavi, Maral P. S.;Buhlmann, Philippe
由于它们的低极性和极化率，氟传感膜是疏水和疏脂的，并表现出非常高的离子选择性。在这里，我们报告了一种新的氟膜离子选择性电极（伊势）具有广泛的传感范围围绕生理相关的pH值。合成了亲氟三[全氟（辛基）丁基]胺（N-[（CH 2）（4）R-f8]（3）），并使用重新设计的电极体作为新的H+离子载体进行测试，该电极体提供了优异的机械密封和大大提高的测量可靠性。在具有挑战性的1 M KCl背景下，这些荧光相ISE表现出从pH 2.2至11.2的感测范围，这是迄今为止报道的基于离子载体的ISE的最宽工作范围之一。测定了对常见干扰离子如K+、Na+和Ca 2+的高选择性（选择性系数：logK（H，K）（pot）=-11.6; logK（H，Na）（pot）=-12.4; logK（H，Ca）（pot）<-10.2）。与碱性较低的三[全氟（辛基）丙基]胺离子载体相比，使用N[（CH 2）（4）R-f8]（3）离子载体及其-（CH 2）（4）-间隔基将氨基与强吸电子的全氟辛基分开改善了电位选择性。N[（CH 2）（4）R-f8]（3）的使用还使得伊势不太容易发生反阴离子故障（即，Donnan失效）的能力，而不是使用具有较长-（CH 2）（5）-间隔基的三[全氟（辛基）戊基]胺，这更有效地保护氨基中心免受全氟辛基基团的影响。此外，我们将常规增塑PVC相pH ISE和氟相pH ISE暴露于10%血清5天。结果表明，PVC相离子选择性电极失去了选择性，而它们的氟相对应物没有。
Because of their low polarity and polarizability, fluorous sensing membranes are both hydrophobic and lipophobic and exhibit very high ion selectivities. Here, we report on a new fluorous-membrane ion-selective electrode (ISE) with a wide sensing range centered around physiologically relevant pH values. The fluorophilic tris[perfluoro(octyl)butyl]amine (N-[(CH2)(4)R-f8](3)) was synthesized and tested as a new H+ ionophore using a redesigned electrode body that provides excellent mechanical sealing and much improved measurement reliability. In a challenging 1 M KCl background, these fluorous-phase ISEs exhibit a sensing range from pH 2.2 to 11.2, which is one of the widest working ranges reported to date for ionophore-based ISEs. High selectivities against common interfering ions such as K+, Na+, and Ca2+ were determined (selectivity coefficients: logK(H, K)(pot) = - 11.6; logK(H, Na)(pot) = - 12.4; logK(H, Ca)(pot) < - 10.2). The use of the N[(CH2)(4)R-f8](3) ionophore with its -(CH2)(4)- spacers separating the amino group from the strongly electron-withdrawing perfluorooctyl groups improved the potentiometric selectivity as compared to the less basic tris[perfluoro(octyl)propyl] amine ionophore. The use of N[(CH2)(4)R-f8](3) also made the ISE less prone to counter anion failure (i.e., Donnan failure) at low pH than the use of tris[perfluoro(octyl)pentyl]amine with its longer -(CH2)(5)- spacers, which more effectively shield the amino center from the perfluorooctyl groups. In addition, we exposed both conventional plasticized PVC-phase pH ISEs and fluorous-phase pH ISEs to 10% serum for 5 days. Results show that the PVC-phase ISEs lost selectivity while their fluorous-phase counterparts did not.