Kakuta Tomomi, Manyuan Nichayanan, Kawasaki Hideya
Department of Chemistry and Materials Engineering, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Osaka, Japan.
Mass Spectrom (Tokyo). 2022;11(1):A0107. doi: 10.5702/massspectrometry.A0107. Epub 2022 Dec 15.
We report that modifying the surface of gold nanoparticles (Au NPs) with 2-mercaptopyridine-3-carboxylic acid (MPyCA) enhances surface-assisted laser desorption/ionization (SALDI) performance in the analysis of small molecules. The MPyCA ligand has a strong UV absorbance at the wavelengths of the typical MALDI laser at 337 nm, resulting in efficient thermal/energy transfer from the Au NPs to analytes during pulse-laser irradiation. In addition, the MPyCA ligand contains carboxylic acid and pyridine groups, providing affinity to various analytes through acid-base interactions. Irganox1010, glucose and meropenem were utilized as model analytes to evaluate SALDI performance because these molecules are generally ionized with difficulty by conventional MALDI-MS. Our results demonstrate that the MPyCA-Au NP based SALDI-MS could detect Irganox1010, glucose and meropenem with stronger ion peaks for these molecules compared to MALDI-MS using CHCA. The limit of detection (LOD) for meropenem was much lower in the case of SALDI (LOD=1 ng/mL) compared to MALDI (LOD=10 μg/mL).
我们报道，用2-巯基吡啶-3-羧酸（MPyCA）修饰金纳米颗粒（Au NPs）的表面，可增强小分子分析中的表面辅助激光解吸/电离（SALDI）性能。MPyCA配体在典型基质辅助激光解吸电离（MALDI）激光的波长337 nm处具有很强的紫外吸收，导致在脉冲激光照射期间从金纳米颗粒到分析物的有效热/能量转移。此外，MPyCA配体含有羧酸和吡啶基团，通过酸碱相互作用对各种分析物具有亲和力。选用抗氧剂1010、葡萄糖和美罗培南作为模型分析物来评估SALDI性能，因为这些分子通常难以通过传统的基质辅助激光解吸电离质谱（MALDI-MS）进行电离。我们的结果表明，与使用α-氰基-4-羟基肉桂酸（CHCA）的MALDI-MS相比，基于MPyCA-Au NP的SALDI-MS能够检测到抗氧剂1010、葡萄糖和美罗培南，且这些分子的离子峰更强。与MALDI（检测限=10μg/mL）相比，美罗培南在SALDI情况下的检测限（LOD）要低得多（LOD=1 ng/mL）。
