Biosensing of Cysteine through the Induction of Oxygen Vacancies in a Cu/Zr Heterostructure Prepared by Supercritical Antisolvent Technique

There has been a growing emphasis on facile preparation of binary heterogeneous composite materials. Leveraging the eco-friendly efficiency of supercritical CO₂ technology, we achieved precise control over the influencing factors of mass transfer, enabling the accurate modulation of the resulting product morphology and properties. In the current study, Cu_xO/ZrO_y composite materials were prepared using this technology and calcined to obtain electrode materials for the detection of cysteine (Cys). Essential comprehensive characterization techniques were employed to elucidate the heterojunction. The resulting electrode demonstrated a linear response to Cys within a concentration range of 0.5 nM to 1 μM, featuring a high sensitivity of 1035 μA·cm^–2·μM^–1 and a low detection limit of 97.3 nM. Thus, establishing a novel avenue for nonenzyme-based electrochemical sensors tailored for biologically active Cys detection through the implementation of a heterogeneous structure.