School of Molecular Sciences, Magnetic Resonance Research Center, Arizona State University , Tempe, Arizona 85287-1604, United States.
Department of Chemistry and Biochemistry, San Diego State University , 5500 Campanile Drive, San Diego, California 92182-1030, United States.
ACS Appl Mater Interfaces. 2017 May 24;9(20):17653-17661. doi: 10.1021/acsami.7b04887. Epub 2017 May 9.
In this work, thermal condensation of alanine adsorbed on fumed silica nanoparticles is investigated using thermal analysis and multiple spectroscopic techniques, including infrared (IR), Raman, and nuclear magnetic resonance (NMR) spectroscopies. Thermal analysis shows that adsorbed alanine can undergo thermal condensation, forming peptide bonds within a short time period and at a lower temperature (∼170 °C) on fumed silica nanoparticle surfaces than that in bulk (∼210 °C). Spectroscopic results further show that alanine is converted to alanine anhydride with a yield of 98.8% during thermal condensation. After comparing peptide formation on solution-derived colloidal silica nanoparticles, it is found that fumed silica nanoparticles show much better efficiency and selectivity than solution-derived colloidal silica nanoparticles for synthesizing alanine anhydride. Furthermore, Raman spectroscopy provides evidence that the high efficiency for fumed silica nanoparticles is likely related to their unique surface features: the intrinsic high population of strained ring structures present at the surface. This work indicates the great potential of fumed silica nanoparticles in synthesizing peptides with high efficiency and selectivity.
在这项工作中，使用热分析和多种光谱技术，包括红外（IR）、拉曼和核磁共振（NMR）光谱，研究了吸附在烟炱二氧化硅纳米颗粒上的丙氨酸的热缩合。热分析表明，吸附的丙氨酸可以在较短的时间内在烟炱二氧化硅纳米颗粒表面上进行热缩合，形成肽键，而在块状物（约 210°C）中的温度要低得多（约 170°C）。光谱结果进一步表明，丙氨酸在热缩合过程中转化为丙氨酸酐，产率为 98.8%。在比较溶液衍生胶体二氧化硅纳米颗粒上的肽形成后，发现与溶液衍生胶体二氧化硅纳米颗粒相比，烟炱二氧化硅纳米颗粒在合成丙氨酸酐方面具有更高的效率和选择性。此外，拉曼光谱提供了证据表明，烟炱二氧化硅纳米颗粒的高效率可能与其独特的表面特征有关：表面存在固有高浓度的应变环结构。这项工作表明，烟炱二氧化硅纳米颗粒在高效和选择性合成肽方面具有巨大的潜力。
