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

Abstract

Abstract A simple solution based deposition process has been used to fabricate Zn doped Co 3 O 4 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 Co 3 O 4 resulted in enhanced electrochemical performance of Zn:Co 3 O 4 material compared to pristine Co 3 O 4 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:Co 3 O 4 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:Co 3 O 4 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.