Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Korea.
Department of Physics, Yonsei University, Seoul 03722, Korea.
Nano Lett. 2020 Aug 12;20(8):5625-5631. doi: 10.1021/acs.nanolett.9b04548. Epub 2020 Apr 17.
The wettability of graphene has been extensively studied and successfully modified by chemical functionalization. Nevertheless, the unavoidable introduction of undesired defects and the absence of systematic and local control over wettability by previous methods have limited the use of graphene in applications. In addition, microscale patterning, according to wettability, has not been attempted. Here, we demonstrate that the wettability of graphene can be systematically controlled and surface patterned into microscale sections based on wettability without creating significant defects, possible by nondestructive hydrogen plasma. Hydrophobic graphene is progressively converted to hydrophilic hydrogenated graphene (H-Gr) that reaches superhydrophilicity. The great contrast in wettability between graphene and H-Gr makes it possible to selectively position and isolate human breast cancer cells on arrays of micropatterns since strong hydrophilicity facilitates the adsorption of the cells. We believe that our method will provide an essential technique for enabling surface and biological applications requiring microscale patterns with different wettability.
石墨烯的润湿性已经得到了广泛的研究，并通过化学功能化成功地进行了修饰。然而，以前的方法不可避免地引入了不需要的缺陷，并且无法对润湿性进行系统和局部控制，这限制了石墨烯在应用中的使用。此外，根据润湿性进行微尺度图案化尚未尝试。在这里，我们证明通过无损的氢等离子体，石墨烯的润湿性可以在不产生明显缺陷的情况下，基于润湿性进行系统控制和表面图案化为微尺度区域。疏水性石墨烯逐渐转化为亲水性氢化石墨烯（H-Gr），从而达到超亲水性。石墨烯和 H-Gr 之间巨大的润湿性对比使得可以选择性地在微图案阵列上定位和隔离人乳腺癌细胞，因为强亲水性有利于细胞的吸附。我们相信，我们的方法将为需要不同润湿性的微尺度图案的表面和生物应用提供一种重要的技术。
