纳米金淀积的多孔硅靶增强样品的激光解吸/电离质谱信号

摘要

The diversity of silicon types and porous silicon structures brought many challenges to desorption/ionization on silicon(DIOS) (matrix-free mass spectroscopy)such as poor repeatability/reproducihility in data and short shelf-life of the sample target.The porous silicon layer deposited with gold nanoparticles was studied in this work as a sample target to enhance the laser desorption/ionization(LDI)of polyethylene glycol(PEG)and two peptides (oxytocin and angiomax).Passivation of the surface Si-H species by gold nanoparticles increases the shelf-life of the target.The morphologies of porous silicon before and after deposition of gold nanoparticles were examined by fieldemission scanning electron microscopy(FE-SEM).The elemental composition of surface species was analyzed by X-ray energy dispersive spectroscopy(EDS).Effect of the deposition time on the quantity of gold nanoparticles and also on the signal enhancement was investigated.The desorption/ionization enhancement of molecules may be due to the integration of porous silicon and gold nanoparticles with unique optical and physical properties.This type of sample target combines the advantages of both DIOS and gold nanoparticles.%硅片类型和多孔硅结构的多样性影响了多孔硅表面的激光解吸/离子化质谱(DIOS)(无辅助基质的激光解吸/电离飞行时间质谱(LDI-TOF-MS))数据的重复性和靶的耐储时间.本工作通过在多孔硅的表面淀积金纳米颗粒并将其作为目标靶来增强软物质分子如聚乙二醇和多肽的激光解吸/电离质谱信号.纳米金的淀积钝化了多孔硅表面的Si-H活性基团,增加了靶的耐储时间.用场发射扫描电镜表征了多孔硅淀积金纳米颗粒前后的形貌,用X射线能量色散光谱法分析金的百分含量,结果表明其含量随沉积时间的延长而增加.激光解吸/电离质谱信号的增强可能是由多孔硅及其支持的金纳米颗粒的光学和物理性质引起的,该类型的样品靶在激光解吸/电离飞行时间质谱的应用上结合了多孔硅和金纳米颗粒的双重优势.