Highly Stable Polymeric Ionic Liquid Modified Electrode to Immobilize Ferricyanide for Electroanalysis of Sulfide

We report here the preparation and application of a highly stable polymeric ionic liquid‐modified electrode to immobilize ferricyanide for sulfide analysis. Good long‐term stability of the modified electrode verifies its potential in sensor applications. The electrocatalytic sulfide oxidation signal at ∼0.0 V vs. Ag/AgCl in pH 7 PBS at the modified electrode was used for sulfide detection by hydrodynamic chronoamperometry and a detection limit of 12.9 nM (S/N=3) was obtained. Practical utility of the system is applied to the determination of sulfide content in hot spring water and ground water.