Simple Solution Deposition of Co3O4 on FTO for Rapid and Selective Nonenzymatic Glucose Detection

There is no permanent treatment for diabetes mellitus yet. This condition is managed by regularly checking blood glucose levels and taking appropriate measures accordingly. Hence, a significant amount of research efforts have been made to develop highly sensitive and affordable glucose sensor. It is well known that the performance of any sensor is highly dependent on the nature and fabrication techniques used for the preparation of the electrodes. Various electrode fabrication techniques such as pulsed laser deposition (PLD), plasma sputtering, atomic layer deposition (ALD), hydrothermal, electrodeposition, electrospinning have been used to fabricate various metal oxide based electrodes for glucose sensing applications. These techniques are not suitable for commercial scale production of economical nonenzymatic glucose sensor. In this study a simple chemical solution deposition process has been used to fabricate Co 3 O 4 electrode as an electrocatalyst for nonenzymatic oxidation of glucose. Several physical and chemical characterisation techniques such as XRD, HRSEM, HRTEM,AFM, EIS, EELS, EDS was used to elucidate the phyiscal and chemical characteristics of the Co 3 O 4 electrode. The as prepared electrode showed fast response time (< 7s), good sensitivity (504.1 µA mM -1 cm -2 ), high selectivity towards glucose at an applied potential of +0.60V in 0.1 M NaOH solution. A detection limit of 3 µM (S/N = 3) was measured for the Co 3 O 4 electrode. The electrode retained 85% of initial current response after 2 months of application. Figure 1 presents the electrochemical performance of the Co 3 O 4 electrode in the presence and absence of 1mM glucose at a scan rate of 25 mVs -1 . Figure 1