Warsaw University of Technology, Faculty of Chemistry, Institute of Biotechnology, Department of Microbioanalytics, 00-664 Warsaw, Poland.
Analyst. 2011 Sep 21;136(18):3770-6. doi: 10.1039/c0an00965b. Epub 2011 Jul 21.
In this work, the possibility of application of free base porphyrin as a lipophilic pH chromoionophore for the preparation of optical cation-selective sensors was investigated. The properties of polymeric membranes, containing porphyrins of different structures, namely tetraphenylporphyrin (TPP) and octaethylporphyrin (OEP), were compared. Changes in equilibrium between protonated and deprotonated form of porphyrin, resulting from variations in ACh concentration, were evaluated. The influence of various factors (kind and quantity of anionic additive and porphyrin in the membrane phase, pH of sample solution) on initial equilibrium was studied. The best membrane composition was chosen as: TPP 3 wt.%, KTFPB 175 mol.% relative to ionophore, PVC:o-NPOE (1 : 4) and measuring buffer solution: 0.05 M MES, pH 4.5. Selectivity, response stability, reversibility and repeatability tests were carried out for chosen sensor. Developed sensor allowed for the determination of a model analyte, acetylcholine, at the concentration range of 10(-5) to 10(-2) M, both in stationary and flow-injection system. Sensor response was reversible and repeatable in the mentioned concentration range.
在这项工作中，研究了游离碱基卟啉作为亲脂性 pH 显色离子对，用于制备光学阳离子选择性传感器的可能性。比较了含有不同结构卟啉（四苯基卟啉（TPP）和八乙基卟啉（OEP））的聚合物膜的性质。评估了由于 ACh 浓度变化导致卟啉质子化和去质子化形式之间平衡的变化。研究了各种因素（膜相中的阴离子添加剂和卟啉的种类和数量、样品溶液的 pH 值）对初始平衡的影响。选择了最佳的膜组成：TPP 3wt.%，KTFPB 相对于离子载体为 175mol.%，PVC:o-NPOE（1:4）和测量缓冲溶液：0.05M MES，pH4.5。对选定的传感器进行了选择性、响应稳定性、可逆性和可重复性测试。开发的传感器允许在 10(-5) 至 10(-2) M 的浓度范围内，在静态和流动注射系统中测定模型分析物乙酰胆碱。在所述浓度范围内，传感器响应是可逆和可重复的。
