Making a selective and sensitive iron (III) ion selection sensor based on nitrobenzo-۱۸-crown-۶ ionophore

Background: Electrochemical sensors are an important subgroup of chemical sensors in which an electrode is used as a signal transducer element. The purpose of the present study is to provide a new, simple and practical method for creating a sensitive sensor to a cationic pollutant of the iron (III) group.   Methods: The penetration of the measured pollutant species into two levels of the membrane’s, interior and exterior, caused a potential difference in the membrane surface. This potential difference depended on the activity of the target species through the corrected Nicolsky-Eisenman equation and based on Nernst equations.   Results: In this study, the selective iron (III) electrode based on a polymer membrane consisting of four main components of nitrobenzo-۱۸-crown-۶ ionophore, lipophilic additive potassium tetra case, ۴-chlorophenyl borate (KTpClPB), and Ortho- nitro-phenyl octyl ether plasticizer (O-NPOE) in PVC with a weight percentage of ۵, ۱.۵, ۶۰.۵, ۳۳, respectively, showed a linear response with a Nernst slope of ۱۹.۷۷ ± ۰.۲۷ in the density range of ۱.۰ × ۱۰-۶ – ۱.۰ × ۱۰-۱ molar of iron (III) cation with a detection limit of ۷.۰ × ۱۰-۷ in a pH-restricted range of ۲.۹-۶.۱. The average dynamic response time of the built-in electrochemical sensor was ۱۵ seconds.   Conclusion: The built-in sensor can be used for ۱۲ weeks with acceptable repeatability. The made electrode has a very high selectivity for iron (III) cation in the presence of significant amounts of one, two, and three-valent intrusive ions of alkali metals, alkaline earth metals, intermediate metals, and heavy metals.

کلیدواژه ها:

nitrobenzo-۱۸-crown-۶ ، Electrochemical sensor ، Dynamic response