Graduate Institute of Nanomedicine and Medical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan.
Nanoscale. 2017 Aug 10;9(31):11119-11125. doi: 10.1039/c7nr04098a.
The design of a homogeneous sample plate to solve the sweet heating spot issues is the key step to expand the applicability of surface-assisted laser desorption/ionization mass spectrometry (SALDI MS). Herein, large-scale and highly oriented Langmuir-Blodgett (LB) films of uniform silver nanocrystals have been fabricated as a highly efficient and matrix-free sample plate for SALDI MS. Three individual silver nanocrystals (cubes, cuboctahedra and octahedra) assembled LB films have been applied as the sample plates for glucose detection by SALDI MS without an additional matrix. The results show that the signal intensity, background noise, signal-to-noise ratio and reproducibility have been significantly improved using LB films as the sample plate in comparison with commercial matrixes of CHCA and DHB. In particular, a relative signal of 5.7% was obtained for LB films of silver cuboctahedra. The significant improvement in the SALDI MS measurement could be attributed to the homogenous dissipation of laser irradiation energy to create a large area of the sweet heating spot on well-oriented silver cuboctahedra-based LB film. This ready-to-use sample plate has the potential for widespread commercial applications in SALDI MS.
设计均质样品板以解决糖加热点问题是扩大表面辅助激光解吸/电离质谱（SALDI MS）适用性的关键步骤。在此，已经制备了大规模且高度取向的均匀银纳米晶体的朗缪尔-布洛杰特（LB）膜，作为 SALDI MS 的高效无基质样品板。三个单独的银纳米晶体（立方体、十二面体和八面体）组装的 LB 膜已被用作 SALDI MS 检测葡萄糖的样品板，无需额外的基质。结果表明，与商用基质 CHCA 和 DHB 相比，使用 LB 膜作为样品板可以显著提高信号强度、背景噪声、信噪比和重现性。特别是，银十二面体 LB 膜的相对信号为 5.7%。SALDI MS 测量的显著改善可归因于激光辐照能量的均匀耗散，从而在基于取向良好的银十二面体的 LB 膜上产生大面积的糖加热点。这种即用型样品板有可能在 SALDI MS 中得到广泛的商业应用。
