Jalil Sohail A, Akram Mahreen, Bhat Javeed A, Hayes Jeffrey J, Singh Subhash C, ElKabbash Mohamed, Guo Chunlei
The Institute of Optics, University of Rochester, Rochester, NY 14627, USA.
GPL State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
Appl Surf Sci. 2020 Mar 15;506:144952. doi: 10.1016/j.apsusc.2019.144952.
Femtosecond laser-induced surface structuring is a promising technique for the large-scale formation of nano- and microscale structures that can effectively modify materials' optical, electrical, mechanical, and tribological properties. Here we perform a systematic study on femtosecond laser-induced surface structuring on gold (Au) surface and their effect on both hydrophobicity and bacterial-adhesion properties. We created various structures including subwavelength femtosecond laser-induced periodic surface structures (fs-LIPSSs), fs-LIPSSs covered with nano/microstructures, conic and 1D-rod-like structures ( 6 μm), and spherical nanostructures with a diameter 10 nm, by raster scanning the laser beam, at different laser fluences. We show that femtosecond laser processing turns originally hydrophilic Au to a superhydrophobic surface. We determine the optimal conditions for the creation of the different surface structures and explain the mechanism behind the formed structures and show that the laser fluence is the main controlling parameter. We demonstrate the ability of all the formed surface structures to reduce the adhesion of Escherichia coli (E. coli) bacteria and show that fs-LIPSSs enjoys superior antibacterial adhesion properties due to its large-scale surface coverage. Approximately 99.03% of the fs-LIPSSs surface is free from bacterial adhesion. The demonstrated physical inhibition of bacterial colonies and biofilm formation without antibiotics is a crucial step towards reducing antimicrobial-resistant infections.
飞秒激光诱导表面结构化是一种很有前景的技术，可用于大规模形成纳米和微米级结构，这些结构能够有效改变材料的光学、电学、机械和摩擦学性能。在此，我们对金（Au）表面的飞秒激光诱导表面结构化及其对疏水性和细菌粘附特性的影响进行了系统研究。通过在不同激光能量密度下对激光束进行光栅扫描，我们创建了各种结构，包括亚波长飞秒激光诱导的周期性表面结构（fs-LIPSSs）、覆盖有纳米/微米结构的fs-LIPSSs、圆锥和一维棒状结构（长度为6μm）以及直径为10nm的球形纳米结构。我们表明，飞秒激光加工可将原本亲水的金转变为超疏水表面。我们确定了创建不同表面结构的最佳条件，解释了所形成结构背后的机制，并表明激光能量密度是主要控制参数。我们展示了所有形成的表面结构减少大肠杆菌（E. coli）细菌粘附的能力，并表明fs-LIPSSs由于其大规模的表面覆盖率而具有优异的抗菌粘附性能。约99.03%的fs-LIPSSs表面没有细菌粘附。在不使用抗生素的情况下对细菌菌落和生物膜形成进行物理抑制，是朝着减少抗微生物感染迈出的关键一步。
