Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, 7330 Stevenson Center, Nashville, Tennessee 37235, USA.
Anal Chem. 2010 Apr 1;82(7):3061-6. doi: 10.1021/ac100251d.
Matrix-assisted laser desorption/ionization-ion mobility-mass spectrometry (MALDI-IM-MS) was used to analyze low mass gold-thiolate fragments generated from thiolate-protected gold nanoparticles (AuNPs). This is the first report of using gas-phase structural separations by IM-MS for the characterization of AuNPs, revealing significant structural variation between organic and gold-thiolate ionic species. Through the separation of background chemical noise, gold-thiolate ion species corresponding to fragments from the AuNP surface can be isolated. In the negative ion mode, many of these fragments correlate to capping structural motifs observed in the literature. In the positive ion mode, the fragment ions do not correlate to predicted structural motifs, but are nearly identical to the positive ions generated from the gold-thiolate AuNP precursor complexes. This suggests that energetic processes during laser desorption/ionization induce a structural rearrangement in the capping gold-thiolate structure of the AuNP, resulting in the generation of positively charged gold-thiolate complexes similar to the precursors of AuNP formation by reduction and negatively charged complexes more representative of the AuNP surface.
基质辅助激光解吸/电离-离子淌度-质谱（MALDI-IM-MS）用于分析从硫醇保护的金纳米粒子（AuNP）生成的低质量金-硫醇片段。这是首次报道使用气相结构分离通过 IM-MS 对 AuNP 进行表征，揭示了有机和金-硫醇离子物种之间的显著结构变化。通过分离背景化学噪声，可以分离出与 AuNP 表面片段相对应的金-硫醇离子物种。在负离子模式下，许多这些片段与文献中观察到的封端结构基序相关。在正离子模式下，碎片离子与预测的结构基序不相关，但与从金-硫醇 AuNP 前体配合物生成的正离子几乎相同。这表明激光解吸/电离过程中的能量过程诱导 AuNP 封端金-硫醇结构的结构重排，导致生成类似于 AuNP 形成的还原前体的带正电荷的金-硫醇配合物和更代表 AuNP 表面的带负电荷的配合物。
