Nanoconfinement‐Guided Construction of Nanozymes for Determining H2O2 Produced by Sonication

AbstractNanomaterials with enzyme‐like activities, termed as nanozymes, have found wide applications in various fields. It has been a long‐term aim to rationally design and synthesize highly active nanozymes and thus to further improve their application performance. Guided by the nanoconfinement effect, we confine cytochrome c (Cyt c) within a mesoporous metal–organic framework (MOF), PCN‐222 nanoparticle (NP), forming a protein/MOF hybrid nanozyme, termed as Cyt c@PCN‐222 NP. The confined Cyt c exhibits around 3–4‐fold higher peroxidase‐like activity than free Cyt c. Due to the increase in the activity of Cyt c, the Cyt c@PCN‐222 NPs exhibit a quite low limit of detection (≈0.13 μM) towards H2O2. Sonication‐induced H2O2 formation in water by using a lab‐quipped ultrasonic cleaner can be sensitively probed, which suggests that H2O2‐sensitive materials should be carefully handled during the utilization of ultrasonic equipment. We speculate that this nanoconfinement strategy can broaden our synthetic methodology for the rational design of nanozymes.