Xu Yichuan, Little Mark W, Murray Kermit K
Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
J Am Soc Mass Spectrom. 2006 Mar;17(3):469-74. doi: 10.1016/j.jasms.2005.12.003. Epub 2006 Feb 14.
We report on the fabrication and performance of a gel microfluidic chip interfaced to laser desorption/ionization (LDI) mass spectrometry with a time-of-flight mass analyzer. The chip was fabricated from poly(methylmethacrylate) with a poly(dimethyl siloxane) cover. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was performed in the channel of the microfluidic chip. After electrophoresis, the cover was removed and either the PDMS chip or the PMMA cover was mounted in a modified MALDI ion source for analysis. Ions were formed by irradiating the channel with 2.95 microm radiation from a pulsed optical parametric oscillator (OPO), which is coincident with IR absorption by N-H and O-H stretch of the gel components. No matrix was added. The microfluidic chip design allowed a decrease in the volume of material required for analysis over conventional gel slabs, thus enabling improvement in the detection limit to a pmol level, a three orders of magnitude improvement over previous studies in which desorption was achieved from an excised section of a conventional gel.
我们报道了一种与具有飞行时间质量分析器的激光解吸/电离（LDI）质谱联用的凝胶微流控芯片的制备及其性能。该芯片由聚甲基丙烯酸甲酯制成，带有聚二甲基硅氧烷盖。在微流控芯片的通道中进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳。电泳后，移除盖子，将聚二甲基硅氧烷芯片或聚甲基丙烯酸甲酯盖安装在改进的基质辅助激光解吸电离（MALDI）离子源中进行分析。通过用来自脉冲光学参量振荡器（OPO）的2.95微米辐射照射通道来形成离子，该辐射与凝胶成分的N-H和O-H伸缩振动的红外吸收相一致。未添加基质。微流控芯片设计使得与传统凝胶板相比，所需分析材料的体积减少，从而能够将检测限提高到皮摩尔水平，比之前从传统凝胶切片实现解吸的研究提高了三个数量级。
