Publications scientifiques
Bruno Boniface Nguelo
Autres affiliations : Laboratoire de Chimie
* (Auteur correspondant)
Autres affiliations : University of Ottawa · Laboratoire de Chimie
Ignas Kenfack Tonlé
Autres affiliations : Université de Dschang · Laboratoire de Chimie
Emmanuel Ngameni
Autres affiliations : Laboratoire de Chimie
Christian Detellier
Electroanalysis
Abstract Electrochemical sensors have been developed by modifying a glassy carbon electrode with organo‐kaolinite hybrid materials. These materials were obtained by the grafting of four ionic liquids (1‐(2‐hydroxyethyl)‐4‐benzylpyridinium chloride, 1‐(2‐hydroxyethyl)‐4‐(tert‐butyl)pyridinium chloride, 1‐(2‐hydroxyethyl)‐4‐ethylpyridinium chloride and 1‐(2‐hydroxyethyl)‐4‐methylpyridinium chloride) on the interlayer aluminol surfaces of kaolinite. With the presence of ionic liquids in the interlayer space of kaolinite, the hybrid materials acquired anion exchange properties and were successfully applied as electrode modifier for the electroanalysis of thiocyanate (SCN − ), an anion of medical and environmental concern. A pre‐concentration/detection strategy was used to overcome the interfering effect of the electrolytic solution. After the optimisation of some key experimental parameters (sodium nitrate as electrolyte, 5 min of accumulation time) calibration curves were plotted. Excellent linearity was obtained in the low concentration region (1×10 −6 M to 4×10 −5 M). The lowest detection limit (15 nM) was obtained with the benzylpyridinium functionalized kaolinite and the highest (60 nM) with the methylpyridinium functionalized kaolinite. Interfering anions (NO 3 − , Cl − , SO 4 2− and CH 3 COO − ) present in the pre‐concentration solution were found to interfere with SCN − but the sensors remained stable and produced reproducible signals. The most sensitive sensor was successfully applied for the amperometric determination of SCN − in human saliva samples.
