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/cm², 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.

中文翻译：

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飞秒脉冲激光对单个蛋白质晶体进行微处理

具有不同微模式的蛋白质在生物传感，结构分析和其他生物医学领域中具有多种应用。然而，由于蛋白质分子的脆弱性，在单个蛋白质晶体上加工微图案仍然是一个挑战。在这项工作中，我们研究了对单个母鸡卵清溶菌酶蛋白晶体的飞秒激光加工。发现优化的激光参数可以实现微图案化而不会破裂蛋白质晶体。讨论了烧蚀形态对激光能量密度和脉冲数的依赖性，以控制加工结果。在高于1 J / cm ²的激光通量下，形成了消融孔。当施加通量低于消融阈值的多脉冲时，由于蛋白质的变性观察到了起泡区域。数值模拟表明，烧蚀结果受电离和能量沉积过程的影响。包括线条，区域和微阵列在内的微图案可以以最小2μm的尺寸进行处理。晶体表面上的加工图案可用于生物传感微阵列和增强晶体生长。这项研究中提出的微处理方法在生物设备和生物医学等不同领域具有潜在的应用。