Supercritical fluid-assisted fabrication of Pt-modified cerium oxide nanozyme based on polymer nanoreactors for peroxidase-like and glucose detection characteristics

To address the key problems of natural proteases in terms of stability, transportation and storage, this work demonstrates the preparation of a Pt/CeO₂ precursor based nanozymes for glucose detection using a user-friendly supercritical CO₂ "nanoreactor" technique. The optimum parameters in this supercritical fluid (SCF) technology were discussed by using the full-factor design. Through the analysis of the valence states of Pt/CeO₂ obtained by the one-step calcination of the precursor, the catalytic mechanism was explored by increasing the Pt⁰ content at the main catalytic active site. Following Michaelis–Menten theory, the detection limit of glucose sensor is around 11.9 μM in a linear range of 100 μM to 500 μM, better than pure CeO₂. Thus, this work demonstrated a rapid, green, and easy approach with controlled preparation of Pt/CeO₂ based on the supercritical antisolvent method, providing great potential for the preparation of metal oxide-based nanozyme and rapid colorimetric detection of glucose.