A Highly Receptive ZnO-Based Enzymatic Electrochemical Sensor for Glucose Sensing

The nano-structured Zinc Oxide (ZnO) has been synthesized by using hydrothermal method and modified via doping of Cobalt (Co), Iron (Fe), a mixture of Co and Fe (Co-Fe) for glucose sensing. The formations of pristine ZnO and doped ZnO have been confirmed by X-Ray diffraction (XRD), which suggests the incorporation of doping elements into the ZnO Matrix. The doped samples show a decrement in photoluminescence intensity in comparison to pristine ZnO, which is an indicative of the formation of competitive pathways for the recombination process. (Co-Fe) doped electrode shows better conductivity than other electrodes, which was later modified with Glucose Oxidase (GO
_x
) for the application of electrochemical sensor. GOx modified (Co-Fe) doped ZnO sensor exhibits enhanced 2-fold sensitivity (
$32.2~\mu \text{A}$
mM
⁻¹
cm
⁻²
) in comparison to the pristine ZnO sensors following the linear range of 0–4 mM, response time 6.21 seconds and
$K_{m}^{\textit {app}}$
value of 0.054 mM. This sensor would be a potential candidate in clinical diagnosis, industry, and food science.