V4O7 microcubes as an alternative to peroxidase/TMB for colorimetric detection of H2O2: Development of glucose sensing method

The study focuses on the synthesis of V4O7 microcubes for the non-enzymatic colorimetric determination of H2O2.Vanadium oxide nanostructures are known for their redox activity and layered structures, making V4O7 a valuable material for sensing applications. The characterization of the prepared sample was done using XPS, XRD, Raman spectroscopy, and SEM techniques. The V4O7 microcube showed a rapid response to H2O2 through direct color change without the need for peroxidase enzymes or TMB. Upon exposure to H2O2, the mixed valence V4O7 oxidized to produce V2O5, enabling sensitive detection of H2O2. The V4O7 sensing system exhibited a wide linear response range from 0.025 to 300 mu M with a low detection limit of 7.6 nM for H2O2 detection. When combined with glucose oxidase, the system could detect glucose levels as low as 18 nM within a linear range of 0.05 mu M to 300 mu M. The proposed sensor demonstrated high selectivity and robust potential for sensing H2O2 in biological samples. The system offers advantages such as fast response, simple operation, naked-eye observation, and cost-effectiveness. The novel sensing system holds promise for visual detection in H2O2 diagnostic clinics, highlighting its potential for practical applications in healthcare settings.