Binderless Solution Processed Zn Doped Co3O4 Film on FTO for Rapid and Selective Non‐enzymatic Glucose Detection

A simple solution based deposition process has been used to fabricate Zn doped Co₃O₄ electrode as an electrocatalyst for non‐enzymatic oxidation of glucose. XRD, HRTEM, SEM, EELS, AFM, EIS was used to characterise the electrode. The addition of Zn as dopant on Co₃O₄ resulted in enhanced electrochemical performance of Zn:Co₃O₄ material compared to pristine Co₃O₄ due to increased charge transferability. The as prepared electrode showed fast response (<7 s) time, good sensitivity (193 μA mM⁻¹ cm⁻²) in the linear range of 5 μM–0.62 mM, good selectivity towards glucose at a relatively lower applied potential of +0.52 V in 0.1 M NaOH solution. A detection limit of ∼2 μM was measured for the Zn:Co₃O₄ electrode. The applied fabrication method resulted in good inter and intra electrode reproducibility as was shown by the lower relative standard deviation values (R.S.D). The electrode retained 70 % of initial current response after 30 days. Although the as prepared Zn:Co₃O₄ electrodes did not result in highest reported sensitivity, and lowest limit of detection; the ease of fabrication and scalability of production, good inter and intra electrode reproducibility makes it a potential candidate for commercial application as glucose sensor.