MBE Grown Vanadium Oxide Thin Films for Enhanced Non‐Enzymatic Glucose Sensing

Abstract

AbstractIn the search for non‐enzymatic alternatives to glucose oxidase, reliable and microchip‐compatible approaches to catalyst development are highly desirable. Herein, the electrochemical behavior of thin films of VOx deposited by molecular beam epitaxy (MBE) on glassy carbon electrodes is reported . A process of partial etching during polarization is observed. Thereafter, highly active and stable traces of VOx act as catalytic centers for glucose electrooxidation. A mechanistic description of the electrochemical process is proposed based on evidence provided by voltammetric measurements. The sensors are calibrated both with potentiometric and amperometric techniques, the former showing a wide linear range (1–10 mM), good sensitivity (14.93 ± 0.39 µA cm−2 × mM–1) and a limit of detection (0.32 m‐M). Unlike most metal oxides, it is shown that VOx on glassy carbon is capable of successfully oxidizing glucose at −0.4 V. Such a one‐of‐kind behavior can have important ramifications for energy‐efficient integrated electrochemical sensors and non‐enzymatic glucose sensing as a whole.