In this study, graphene oxide-octadecylsilane incorporated monolithic nano-columns were developed for protein analysis by nano liquid chromatography (nano LC). The monolithic column with 100 μm id was first prepared by an in situ polymerization using ethylene dimethacrylate (EDMA), 3-chloro-2-hydroxypropylmethacrylate (HPMA-Cl), and methacryloyl graphene oxide nanoparticles (MGONPs). MGONPs were synthesized by the treatment of 3-(trimethoxysilyl)propylmethacrylate (TMSPM) and GO. Tetrahydrofuran (THF) and dodecanol were used as the porogenic solvent. The resulting column was functionalized by dimethyloctadecylch lorosilane (DODCS) for the enhancement of hydrophobicity. The functionalization greatly improved the baseline separation of hydrophobic compounds such as polyaromatic hydrocarbons (PAHs). The optimized monolith with respect to total polymerization mixture was characterized by using Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) X-ray diffraction (XRD) and chromatographic analyses. The blank monoliths without functionalization exhibited poor separation while a good separation performance of MGONPs functionalized monoliths was achieved. The monolith with 100 μm id was evaluated in protein separation in nano LC using RNase A, Cytochrome C, Lysozyme, Trypsin, and Ca isozyme II as the test proteins. It was shown that protein separation mechanism was based on large π-system of GO and hydrophobicity of the monolithic structure. Theoretical plates number up to 57 600 plates were achieved. The nano-column with 50 μm id was also prepared using the same polymerization mixture under the same chemical conditions. These nano-columns were employed for protein separation by nano LC, and the dependence of both nano-column performance on the internal diameter was also discussed.

中文翻译：

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氧化石墨烯-十八烷基硅烷结合了内径 50 μm 和内径 100 μm 的整体纳米柱，用于通过纳米液相色谱分离小分子和蛋白质

在这项研究中，开发了掺入氧化石墨烯-十八烷基硅烷的整体纳米柱，用于通过纳米液相色谱 (nano LC) 进行蛋白质分析。首先通过原位制备内径为 100 μm 的整体柱使用二甲基丙烯酸乙酯 (EDMA)、3-氯-2-羟丙基甲基丙烯酸酯 (HPMA-Cl) 和甲基丙烯酰氧化石墨烯纳米粒子 (MGONPs) 进行聚合。MGONPs 通过处理 3-(三甲氧基甲硅烷基)丙基甲基丙烯酸酯 (TMSPM) 和 GO 合成。四氢呋喃 (THF) 和十二烷醇用作致孔溶剂。所得色谱柱通过二甲基十八烷基氯硅烷 (DODCS) 功能化以增强疏水性。功能化极大地改善了疏水化合物如多环芳烃 (PAH) 的基线分离。通过使用傅里叶变换红外光谱 (FT-IR)、扫描电子显微镜 (SEM) X 射线衍射 (XRD) 和色谱分析来表征相对于总聚合混合物的优化整体。未进行功能化的空白单块分离效果较差，而 MGONPs 功能化单块的分离性能良好。使用 RNase A、细胞色素 C、溶菌酶、胰蛋白酶和 Ca 同工酶 II 作为测试蛋白质，在 nano LC 中对具有 100 μm id 的整体进行蛋白质分离评估。结果表明，蛋白质分离机制是基于GO的大π系统和整体结构的疏水性。理论塔板数达到 57 600 块。还使用相同的聚合混合物在相同的化学条件下制备了内径为 50 μm 的纳米柱。这些纳米柱被用于通过纳米LC分离蛋白质，并讨论了两种纳米柱性能对内径的依赖性。