Yu Jiachen, Jiang Lan, Yan Jianfeng, Li Wenqi
Key Laboratory for Advanced Materials Processing Technology, Ministry of Education of China, State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China.
Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China.
ACS Biomater Sci Eng. 2020 Nov 9;6(11):6445-6452. doi: 10.1021/acsbiomaterials.0c01023. Epub 2020 Sep 23.
Proteins with different micropatterns have various applications in biosensing, structural analysis, and other biomedical fields. However, processing of micropatterns on single protein crystals remains a challenge due to the fragility of protein molecules. In this work, we studied femtosecond laser processing on single hen egg white lysozyme protein crystals. Optimized laser parameters were found to achieve micropatterning without cracking of protein crystals. The ablation morphology dependence on the laser fluence and the pulse number was discussed to control the processing results. Under a laser fluence higher than 1 J/cm, the ablation hole was formed. While multipulses with fluence lower than the ablation threshold were applied, the foaming area was observed due to the denaturation of protein. The numerical simulation shows that the ablation results were influenced by the ionization and energy deposition process. Micropatterns including lines, areas, and microarrays can be processed with a minimum size of 2 μm. Processed patterns on the crystal surface can be used for biosensing microarrays and the enhancement of crystal growth. The microprocessing method proposed in this study has potential applications in different fields including biodevices and biomedicine.
