State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 163 xianlin Road, Nanjing, 210023, P. R. China.
Chem Asian J. 2024 Jan 15;19(2):e202300900. doi: 10.1002/asia.202300900. Epub 2023 Dec 4.
Enzyme-powered micro/nanomotors that can autonomously move in biological environment are attractive in the fields of biology and biomedicine. The fabrication of enzyme-powered micro/nanomotors normally focuses on constructing Janus structures of micro/nanomaterials, based on the intuition that the Janus coating of enzymes can generate driving force from asymmetric catalytic reactions. Here, in the fabrication of catalase-powered silica micro/nanomotors (C-MNMs), an archetypical model of enzyme-powered micro/nanomotors, we find the silica size rather than asymmetric coating of catalase determines the motion ability of C-MNMs. The effects of size and asymmetry have been investigated by a series of C-MNMs at various sizes (0.5, 2, 5 and 10 μm) and asymmetric levels (full-, half- and most-coated with catalase). The motion performance indicates that 500 nm and 2 μm C-MNMs show obvious increases (varying from 134% to 618%) of diffusion coefficient, but C-MNMs bigger than 5 μm have no self-propulsion behaviour at all, regardless of asymmetric levels. In addition, although asymmetry facilitates enhanced diffusion of C-MNMs, only 2 μm C-MNMs are sensitive to asymmetric level. This work elucidates the primary and secondary roles of size and asymmetry in the preparation of C-MNMs, paving the way to fabricate enzyme-powered micro/nanomotors with high motion performance in future.
在生物学和生物医学领域，能够在生物环境中自主运动的酶驱动微/纳米马达具有吸引力。酶驱动微/纳米马达的制造通常侧重于构建微/纳米材料的 Janus 结构，其依据的直觉是酶的 Janus 涂层可以从不对称催化反应中产生驱动力。在这里，在过氧化氢酶驱动的二氧化硅微/纳米马达（C-MNMs）的制造中，作为酶驱动微/纳米马达的典型模型，我们发现二氧化硅的尺寸而不是过氧化氢酶的不对称涂层决定了 C-MNMs 的运动能力。通过一系列不同尺寸（0.5、2、5 和 10 μm）和不对称水平（完全、半和大部分涂有过氧化氢酶）的 C-MNMs 研究了尺寸和不对称的影响。运动性能表明，500nm 和 2μm 的 C-MNMs 的扩散系数明显增加（从 134%增加到 618%），但大于 5μm 的 C-MNMs 根本没有自推进行为，无论不对称水平如何。此外，尽管不对称有助于提高 C-MNMs 的扩散性，但只有 2μm 的 C-MNMs 对不对称水平敏感。这项工作阐明了尺寸和不对称在 C-MNMs 制备中的主要和次要作用，为未来制造具有高运动性能的酶驱动微/纳米马达铺平了道路。
