A ZIF-67 derived Co 3 O 4 dodecahedron shaped microparticle electrode based extended gate field-effect transistor for non-enzymatic glucose detection towards the diagnosis of diabetes mellitus

The present study focuses on non-enzymatic glucose detection using an extended gate field-effect transistor (EGFET) based on zeolitic imidazole framework-67 (ZIF-67) derived cobalt tetraoxide (Co3O4) dodecahedron shaped microparticles. XRD has confirmed the cubic phase of Co3O4. HR-SEM images have highlighted hollow Co3O4 dodecahedra with an average particle size of 1.72 mu m. A cost-effective single-use ZIF-67 derived Co3O4 electrode has been fabricated that covers the range of glucose concentration from 1.5 mM to 42 mM (linear range: 1.5 to 10.5 mM) and has a fast response time of <4 s. The sensitivity is calculated to be 50 mu A mM(-1) cm(-2). Our prepared electrode has demonstrated a good selective response against other interfering molecules like sucrose, lactose, fructose, uric acid, and ascorbic acid. The concentration of the interfering molecules is maintained similar to the physiological conditions of human blood. As a maiden attempt, the influence of glucose concentration on the surface potential of the sensing electrode has been investigated using a scanning Kelvin probe (SKP). We have found that the work function decreases with the increase of glucose concentration. Overall, EGFET and SKP studies have revealed that the ZIF-67 derived Co3O4 dodecahedron shaped microparticle based electrode is suitable for rapid detection of glucose.