Fabrication of a flexible carbon cloth based solid contact iodide selective electrode

Abstract

Elimination of the inner filling electrolyte of classical ISEs to overcome their associated drawbacks is the major driving force for the evolution of solid contact ISEs. Carbon cloth is a cheap and readily available material which can easily replace the existing carbon nanotubes/conducting polymer based solid contact ISEs. The present work is focussed on the fabrication of carbon cloth based solid contact iodide ISEs and their application studies. The electrode exhibits a Nernstian response in the 10⁻⁶ to 10⁻¹ M concentration range and a quantifiable non-Nernstian response in the 10⁻⁷ to 10⁻⁶ M concentration range. A lower limit of detection of 1 × 10⁻⁷ M is obtained. A plausible interfacial ion to electron transfer mechanism in carbon cloth based ISEs is illustrated. The electrode shows good sensitivity, selectivity, stability and response time compared to the existing solid contact iodide ISEs. The quantitative recovery of iodide from natural waters and table salt unequivocally establishes the suitability of CC-I-ISE in real sample analysis.