Functionalized surface for electrochemical sensing of electrochemically inactive alkali metal ion

Abstract

The binding of Na⁺ ion to the ionophore 4-aminobenzo-crown-5 has been monitored by cyclic voltammetry using the redox couple Fe(CN)₆^3-/Fe(CN)₆^4- as a mediator redox probe. The recognition properties of the ionophore covalently bound to 11-MUA self assembled monolayer on gold surface is found to be selective for Na⁺ ion over Li⁺ and K⁺ ions. The self-assembled sensor interface is highly stable, reproducible and shows good sensitivity for detection of Na⁺ ion. The host-guest recognition of the simple crown ether derivative makes the system highly promising for real-time applications for selective detection of electrochemically inactive alkali metals by electrochemical transducer.