Reducing Valence States of Co Active Sites in a Single-Atom Nanozyme for Boosted Tumor Therapy

Hui Wang, Yan Wang, Lilin Lu, Qian Ma, Ruxin Feng, Suying Xu, Tony D. James, Leyu Wang

Research output: Contribution to journalArticlepeer-review

49 Citations (SciVal)


The construction of biocompatible and trackable-imaging single-atom nanozymes (SAzymes) with efficient catalytic activities is particularly desirable. Here, cobalt/titanium oxide (Co/TiO2) SAzymes are presented with cobalt atomically dispersed on nanoporous hollow TiO2 using a cation-exchange strategy. Significantly, by varying the calcination conditions, the enzyme-like activity can be enhanced tenfold. It is determined that different calcination treatments result in valence state shifts of the Co active site due to changes in the amounts of defects, which affects the catalytic kinetics. Moreover, Co/TiO2 SAzymes exhibit good intrinsic biocompatibility and excellent tolerance toward the biological medium, while the hollow structure facilitates the loading of drugs and imaging agents for image-guided chemo-chemodynamic therapy via intravenous injection. This study not only provides a paradigm shift for the preparation of biocompatible SAzymes but also presents new insights for modulating the catalytic activity of SAzymes.

Original languageEnglish
Article number2200331
JournalAdvanced Functional Materials
Issue number28
Early online date13 Apr 2022
Publication statusPublished - 11 Jul 2022

Bibliographical note

Funding Information:
This research was supported in part by the National Natural Science Foundation of China (21725501 and 21874007), Beijing Municipal Natural Science Foundation (2212011), and the Fundamental Research Funds for the Central Universities (PY2101 and XK1901). T.D.J. wishes to thank the Royal Society for a Wolfson Research Merit Award and the Open Research Fund of the School of Chemistry and Chemical Engineering, Henan Normal University for support (2020ZD01).


  • F magnetic resonance imaging
  • cation-exchange strategy
  • charge regulation
  • chemodynamic therapy
  • single-atom nanozyme

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics


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