A potassium-selective electrochemical sensor based on crown-ether functionalized self assembled monolayer

A potassium ion (K+) selective chemical sensor based on self assembled monolayer of 4-aminobenzo-18-Crown-6 ether as selective ionophore has been developed. Host-guest complexation of potassium ions and ionophore was confirmed by conductance studies, UV–Vis and FTIR Spectroscopic measurements. The binding of potassium ion to the ionophore at sensor surface was monitored using a redox probe [Ru(NH3)6]3+/[Ru(NH3)6]4+ as ‘reporter ion’ employing cyclic voltammetry and differential pulse voltammetry. The sensor is found to be responsive to 1μM to 10mM K+ and selective over Li+, NH4+ and large excess of Na+ in solution.