Dong Yue, Wang Lu, Wang Jie, Wang Shijie, Wang Yu, Jin Dongdong, Chen Peng, Du Wei, Zhang Li, Liu Bi-Feng
Britton Chance Center for Biomedical Photonics at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
Department of Mechanical and Automation Engineering, Chinese University of Hong Kong, Shatin NT, Hong Kong SAR, China.
ACS Nano. 2020 Dec 22;14(12):16600-16613. doi: 10.1021/acsnano.0c07067. Epub 2020 Oct 29.
Nature provides diverse inspirations for constructing mobile and functionalized micromachines. For example, artificial helical micro-/nanomotors inspired by bacteria flagella that can be precisely steered for various applications have been constructed by utilizing materials with excellent functions. Graphene-based materials show outstanding properties, and, to date, have not been considered to construct helical micromotors and investigate their potential applications. Here, we propose an interesting "microscale liquid rope-coil effect" strategy to stably and simply fabricate graphene oxide-based helical micromotors (GOFHMs) with high throughput by the capillary microfluidics technique. A range of desirable GOFHMs with different pitch, length, and linear diameter are tailored by smart parameter setting in microfluidic system (flow velocity, concentration, and so on). Afterward, graphene-based helical micromotors (GFHMs) are easily acquired by the reduction of GOFHMs and further drying. Actuated by rotating magnetic field, GFHMs show capability to conduct programmed locomotion in a microchannel. As a proof-of-concept demonstration, GFHMs and Ag modified GFHMs have been successfully applied to water remediation, which exhibits excellent removal efficiency of chemical and biological pollutants. Meanwhile, doxorubicin is modified onto GFHMs for the application of drug delivery. Accordingly, we believe that GFHMs have great potential in a variety of fields by modifying graphene with other nanoparticles or functional molecules.
大自然为构建可移动且功能化的微机器提供了多样的灵感。例如，受细菌鞭毛启发的人造螺旋微/纳米马达，可通过利用具有优异功能的材料来构建，从而能够针对各种应用进行精确操控。基于石墨烯的材料展现出卓越的性能，然而，迄今为止，尚未被考虑用于构建螺旋微马达并研究其潜在应用。在此，我们提出一种有趣的“微尺度液体绳卷效应”策略，通过毛细管微流控技术稳定且简便地高通量制备基于氧化石墨烯的螺旋微马达（GOFHMs）。通过在微流控系统中巧妙设置参数（流速、浓度等），可定制一系列具有不同螺距、长度和线性直径的理想GOFHMs。随后，通过还原GOFHMs并进一步干燥，可轻松获得基于石墨烯的螺旋微马达（GFHMs）。在旋转磁场驱动下，GFHMs展现出在微通道中进行编程运动的能力。作为概念验证演示，GFHMs和银修饰的GFHMs已成功应用于水修复，对化学和生物污染物表现出优异的去除效率。同时，将阿霉素修饰到GFHMs上用于药物递送应用。因此，我们相信通过用其他纳米颗粒或功能分子修饰石墨烯，GFHMs在各种领域具有巨大潜力。
