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 'reporterion' employing cyclic voltammetry and differential pulse voltammetry. The sensor is found to be responsive to 1 mu M to 10 mM K+ and selective over Li+, NH4+ and large excess of Na+ in solution.