Amorphous RuO2 Nanozymes with an Excellent Catalytic Efficiency Superior to Natural Peroxidases

Abstract

Developing efficient peroxidase-like nanozymes to surpass natural enzymes remains a significant challenge. Herein, an amorphous RuO₂ nanozyme with peroxidase-like activity is synthesized for activating H₂O₂ with a specific activity of 1492.52 U mg⁻¹, outperforming the crystalline RuO₂ nanozymes by a factor of 22 and far superior to natural peroxidases. Amorphous RuO₂ nanozymes with long-range disordered atomic arrangements can effectively elongate the O─O bonds in H₂O₂. Abundant oxygen vacancies in amorphous RuO₂ nanozymes lead to an upshift of the d-band center, enhancing the exceptional adsorption strength of H₂O₂, which improve the electron transfer efficiency and ensure superior peroxidase-like activity. Accordingly, a nanozyme-linked immunosorbent assay is developed for the precise and sensitive detection of prostate-specific antigens with a detection limit as low as 0.52 pg mL⁻¹. This study introduces a simple approach for developing high-performance peroxidase-like nanozymes to improve the analytical performances of prostate-specific antigens in clinical diagnostics.