Novel non-enzymatic glucose sensing material based on pillared clay modified with cobalt

Abstract

Cobalt oxide supported on pillared clay was synthesized and used as modifier of carbon paste electrode. Cyclic Voltammetry and Impedance Spectroscopy were employed to evaluate the performance of investigated electrode in NaOH solution with and without glucose. The experimental conditions such as concentration of OH− ion and the amount of modifier in carbon paste electrode were optimized in order to achieve the highest response for the investigated electrode material. The results showed that the catalytic activity toward glucose increased with the increase of OH- concentration up to the highest investigated concentration (1 M). The highest sensitivity and lowest detection limit were obtained for carbon paste electrodes modified with the equal amounts of carbon black and modifier. Under optimal conditions chronoamperometric measurements revealed that investigated electrode has two linear dynamic ranges. In the first range up to 1.5 mM sensitivity was 71.96 μAmM-1 cm-2 with LOD = 2.13 μM, while in the second range (2–10 mM) approx. two times lower sensitivity and higher LOD were found. The electrode exhibited excellent reproducibility, repeatability and long term stability. The high quality electrochemical performances together with low cost and easiness of synthesis makes cobalt oxide supported on pillared clay appealing sensing material for enzyme-free glucose detection