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 μA 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 ^app value of 0.054 mM. This sensor would be a potential candidate in clinical diagnosis, industry, and food science.