Milasinovic Slobodan, Liu Yaoming, Gasper Gerald L, Zhao Youbo, Johnston Joanna L, Gordon Robert J, Hanley Luke
Department of Chemistry, m/c 111, University of Illinois at Chicago, Chicago, IL 60607-7061.
J Vac Sci Technol A. 2010 Jul 1;28(4):647-651. doi: 10.1116/1.3397736.
Sample ablation by pulsed lasers is one option for removing material from a sample surface for in situ depth profiling during imaging mass spectrometry, but ablation is often limited by laser-induced damage of the remaining material. A preliminary evaluation was performed of sub-100 fs, 800 nm pulsed laser ablation for depth profiling of bacterial biofilms grown on glass by the drip flow method. Electron and optical microscopy were combined with laser desorption vacuum ultraviolet postionization mass spectrometry to analyze biofilms before and after ablation. Ultrashort laser pulses can ablate 10 - 100 µm thick sections of bacterial biofilms, leaving behind a layer of lysed cells. However, mass spectra from intact and ablated biofilms doped with antibiotic are almost identical, indicating little chemical degradation by ablation. These results are consistent with prior observations from laser surgery and support the use of ultrashort pulse laser ablation for minimally disruptive depth profiling of bacterial biofilms and intact biological samples.
在成像质谱分析过程中，通过脉冲激光进行样品烧蚀是从样品表面去除材料以进行原位深度剖析的一种选择，但烧蚀通常受限于激光对剩余材料的损伤。对亚100飞秒、800纳米的脉冲激光烧蚀进行了初步评估，用于通过滴流法在玻璃上生长的细菌生物膜的深度剖析。电子显微镜和光学显微镜与激光解吸真空紫外后电离质谱联用，以分析烧蚀前后的生物膜。超短激光脉冲可以烧蚀10 - 100微米厚的细菌生物膜切片，留下一层裂解细胞。然而，掺杂抗生素的完整生物膜和烧蚀后生物膜的质谱几乎相同，表明烧蚀造成的化学降解很小。这些结果与激光手术的先前观察结果一致，并支持使用超短脉冲激光烧蚀对细菌生物膜和完整生物样品进行微创深度剖析。
