Fine scalloped petal-like Co3O4 for electro-oxidation of glucose

Abstract A simple hydrothermal synthesis of petal-like cobalt oxide (Co 3 O 4 ) is presented as part of our attempt to improve the characteristic properties of the novel structured metal oxide for its responsive behaviour towards glucose in electrochemical non-enzymatic glucose sensing. The structure and shape of the synthesised material were analysed by thermogravimetric analysis, powder X-ray diffraction, field-emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). The studies show that the synthesised electrode material has unique microstructures that enable bulk diffusion of electrolyte ions, homogeneous structuration, and increased reactive equivalents. It further exhibits channel-type porosity, an extremely accessible surface area with a suitable surface charge, and a uniquely tunable structure. These properties of the perfect nanocrystalline structure make the material better for sensing applications, with enhanced electrochemical sensing performance. The electrochemical tests revealed that glucose oxidation was diffusion-limited at 0.5 V (versus Ag/AgCl) in an alkaline medium (0.15 mol dm − 3 NaOH). The findings illustrate superior interaction between diffusion-controlled electro-oxidation processes and kinetic surface adsorption/selectivity of glucose on the petal-like Co 3 O 4 material surface. The electrode material demonstrated strong electrocatalytic activity towards glucose. The investigations revealed that the synthesised cobalt oxide electrode material is a suitable platform for the oxidation of glucose and the sensitive identification of target biomolecules, such as glucose moieties, with potential applications in clinical diagnosis and healthcare monitoring.