本文基于国外最新研究工作,系统总结了电位型传感器中的一种新型传感膜——氟液相传感膜。对构成氟液相传感膜的所有组分:氟溶剂、溶解在氟溶剂中的亲氟离子交换剂和亲氟离子载体以及对氟溶剂起支撑作用的惰性微孔支撑膜等进行了全面归纳,重点讨论了这4种因素对传感器性能的影响。指出目前使用的亲氟离子交换剂分子和亲氟离子载体分子均含有2—8根链长为6—10的全氟碳链。氟液相传感膜具有优于传统PVC膜的检测下限,其中通过三维有序大孔碳以固体接触方式构建的氟液相传感膜电位传感器对Ag+的探测下限可达3.8×10-11mol/L。氟液相传感膜还具有十分出色的选择性,无任何离子载体的空白氟液相传感膜的选择系数对数值log Kpi,oJt的跨越宽度达16—18,比无载体的PVC膜宽8个数量级。这类全新的氟液相传感膜构建的电位型离子传感器将以其独特的优势在环境监测、食品卫生,尤其是在医疗诊断、生物物质检测中展示出不可替代的作用。
New fluorous liquid sensing membranes for the fabrication of potentiometric sensors are systematically summarized. Fluorous solvents, fluorophilic ion-exchangers and fluorophilic ionophores doped in the fluorous solvents, as well as inert fluorous porous supports, are reviewed thoroughly. The influence of the four factors on the performance of potentiometric sensors is concentrated. It is pointed out that both the fluorophilic ion- exchangers and ionophores used so far contain 2--8 perfluoroalkyl chains which are composed of 6--10 carbon atoms in each chain. Such a fluorous liquid phase sensing membrane possesses a superior lower detection limit compared with conventional poly(vinyl chloride)(PVC) membranes. For Ag( I ) potentiometric sensor based on the fluorous liquid membrane with solid contact through three-dimensionally ordered macroporous (3DOM) carbon, the lower detection limit can achieve 3.8 -10-H mol/L. Moreover, the potentiometric sensors based on the fluorous membranes demonstrate excellent selectivity. Logarithmic selectivity coefficient log Ki,j pot of a blank fluorous membrane without ionophore spans a remarkably wide range of more than 16--18 orders of magnitude, which is 8 orders of magnitude wider than that of conventional PVC membrane without ionophore. The unique new potentiometric sensors based on fluorous liquid phase sensing membranes could play an important role in many areas such as environmental monitoring, food safety, especially in medical diagnosis and detection for biomaterials.