Xia Chunchao, Zhang Huan, Xie Mengmeng, Che Jiaying, Feng Quanqing, Zhang Yihan, Ma Guohang, Liu Minrui, Hu Sixian, He Yuan, Liu Xiaoli, Li Zhenlin, Fan Haiming
Department of Radiology, West China Hospital, Sichuan University, China.
Center for Nanomedicine and Engineering, Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, China.
J Mater Chem B. 2025 Jul 16;13(28):8434-8445. doi: 10.1039/d5tb00626k.
Ferrite nanoparticles, known for their enzyme-like catalytic activity, have gained significant attention as innovative nanozymes for various catalysis medicine applications. However, the relationship between catalytic activity and ultrasmall ferrite nanoparticle composition remains unclear, which hinders the development of ferrite-based nanozymes with high catalytic performance. Here, we have synthesized a series of ultrasmall ferrite nanozymes for studying their composition dependent peroxidase (POD)-like activity. Initially, their size and surface charge were regulated to assess their impact on POD-like activity. The results indicate that smaller ferrite nanozymes with a negative charge exhibited superior activity when using TMB as the substrate. Subsequently, we examined the ultrasmall ferrite nanozymes with the same size and surface charge but different compositions (CoFeO, MnFeO, and γ-FeO), and comprehensively investigated the effect of composition on POD-like activity. The results show that the POD-like activity is closely related to the composition of the ultrasmall ferrite nanozymes and the activity order towards TMB is found to be CoFeO > MnFeO > γ-FeO. By comparing the catalytic performance of nanoparticles with different compositions, the influence of composition on their activity is elucidated. Furthermore, we determined that the optimal pH and temperature for the POD-like catalytic activity of ultrasmall CoFeO nanozyme were pH = 4-4.5 and 30 °C. Under these optimal catalytic conditions, the ultrasmall CoFeO nanozymes exhibited a higher POD-like activity, resulting in increased tumor cell staining intensity. This suggests that ultrasmall CoFeO nanozymes may serve as a viable alternative to horseradish peroxidase for immunohistochemical staining applications. This work provides experimental evidence for designing efficient ultrasmall ferrite catalysts for nanozyme catalysis medicine applications.
铁氧体纳米颗粒以其类酶催化活性而闻名，作为用于各种催化医学应用的创新纳米酶受到了广泛关注。然而，催化活性与超小铁氧体纳米颗粒组成之间的关系仍不清楚，这阻碍了具有高催化性能的铁氧体基纳米酶的发展。在此，我们合成了一系列超小铁氧体纳米酶，以研究其组成依赖性过氧化物酶（POD）样活性。首先，调节它们的尺寸和表面电荷，以评估其对POD样活性的影响。结果表明，以TMB为底物时，带负电荷的较小铁氧体纳米酶表现出优异的活性。随后，我们研究了尺寸和表面电荷相同但组成不同（CoFeO、MnFeO和γ-FeO）的超小铁氧体纳米酶，并全面研究了组成对POD样活性的影响。结果表明，POD样活性与超小铁氧体纳米酶的组成密切相关，对TMB的活性顺序为CoFeO > MnFeO > γ-FeO。通过比较不同组成纳米颗粒的催化性能，阐明了组成对其活性的影响。此外，我们确定了超小CoFeO纳米酶POD样催化活性的最佳pH和温度为pH = 4-4.5和30°C。在这些最佳催化条件下，超小CoFeO纳米酶表现出更高的POD样活性，导致肿瘤细胞染色强度增加。这表明超小CoFeO纳米酶可能作为辣根过氧化物酶用于免疫组织化学染色应用的可行替代品。这项工作为设计用于纳米酶催化医学应用的高效超小铁氧体催化剂提供了实验证据。
