Japan Advanced Institute of Science and Technology, School of Material Science, 1-1 Asahidai, Nomi City, Ishikawa 923-1292, Japan.
Analyst. 2012 May 7;137(9):2006-10. doi: 10.1039/c2an16237g. Epub 2012 Feb 16.
We analyzed oligonucleotides by nanoparticle-assisted laser desorption/ionization (nano-PALDI) mass spectrometry (MS). To this end, we prepared several kinds of nanoparticles (Cr-, Fe-, Mn-, Co-based) and optimized the nano-PALDI MS method to analyze the oligonucleotides. Iron oxide nanoparticles with diammonium hydrogen citrate were found to serve as an effective ionization-assisting reagent in MS. The mass spectra showed both M - H and M + xMe(2+)- H (Me: transition metal) peaks. The number of metal-adducted ion signals depended on the length of the oligonucleotide. This phenomenon was only observed using bivalent metal core nanoparticles, not with any other valency metal core nanoparticles. Our pilot study demonstrated that iron oxide nanoparticles could easily ionize samples such as chemical drugs and peptides as well as oligonucleotides without the aid of an oligonucleotide-specific chemical matrix (e.g., 3-hydroxypicolinic acid) used in conventional MS methods. These results suggested that iron-based nanoparticles may serve as the assisting material of ionization for genes and other biomolecules.
我们通过纳米颗粒辅助激光解吸/电离（nano-PALDI）质谱（MS）分析了寡核苷酸。为此，我们制备了几种纳米颗粒（Cr、Fe、Mn、Co 基），并优化了 nano-PALDI MS 方法来分析寡核苷酸。发现柠檬酸氢二铵氧化铁纳米颗粒在 MS 中可用作有效的电离辅助试剂。质谱显示了M - H和M + xMe(2+)- H（Me：过渡金属）峰。金属加合离子信号的数量取决于寡核苷酸的长度。这种现象仅在用二价金属核纳米颗粒观察到，而用其他任何价态金属核纳米颗粒都观察不到。我们的初步研究表明，氧化铁纳米颗粒可以无需使用传统 MS 方法中寡核苷酸特异性化学基质（例如 3-羟基吡啶甲酸），轻松地对化学药物、肽以及寡核苷酸等样品进行离子化。这些结果表明，铁基纳米颗粒可能可作为基因和其他生物分子的电离辅助材料。
