Qu Qishu, Xuan Han, Zhang Kehua, Ding Yi, Xu Qin
Key Laboratory of Functional Molecule Design and Interface Process, School of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei, P. R. China.
College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, P. R. China.
Electrophoresis. 2016 May;37(10):1367-75. doi: 10.1002/elps.201500548.
Graphene oxide (GO) has been considered as a promising stationary phase for chromatographic separation. However, the very strong adsorption of the analytes on the GO surface lead to the severe peak tailing, which in turn resulting in decreased separation performance. In this work, GO and silica nanoparticles hybrid nanostructures (GO/SiO2 NPs@column) were coated onto the capillary inner wall by passing the mixture of GO and silica sol through the capillary column. The successful of coating of GO/SiO2 NPs onto the capillary wall was confirmed by SEM and electroosmotic flow mobilities test. By partially covering the GO surface with silica nanoparticles, the peak tailing was decreased greatly while the unique high shape selectivity arises from the surface of remained GO was kept. Consequently, compared with the column modified with GO (GO@column), the column modified with GO and silica nanoparticles through layer-by-layer method (GO-SiO2 NPs@column), or the column modified with silica nanoparticles (SiO2 NPs@column), GO/SiO2 NPs@column possessed highest resolutions. The GO/SiO2 NPs@column was applied to separate egg white and both acidic and basic proteins as well as three glycoisoforms of ovalbumin were separated in a single run within 36 min. The intra-day, inter-day, and column-to-column reproducibilities were evaluated by calculating the RSDs of the retention of naphthalene and biphenyl in open-tubular capillary electrochromatography. The RSD values were found to be less than 7.1%.
氧化石墨烯（GO）被认为是一种很有前景的色谱分离固定相。然而，分析物在GO表面的极强吸附导致严重的峰拖尾，进而导致分离性能下降。在本工作中，通过使GO和硅溶胶的混合物通过毛细管柱，将GO和二氧化硅纳米颗粒杂化纳米结构（GO/SiO₂ NPs@柱）涂覆在毛细管内壁上。通过扫描电子显微镜（SEM）和电渗流迁移率测试证实了GO/SiO₂ NPs成功涂覆在毛细管壁上。通过用二氧化硅纳米颗粒部分覆盖GO表面，峰拖尾大大减少，同时保留的GO表面产生的独特高形状选择性得以保持。因此，与用GO改性的柱（GO@柱）、通过层层法用GO和二氧化硅纳米颗粒改性的柱（GO-SiO₂ NPs@柱）或用二氧化硅纳米颗粒改性的柱（SiO₂ NPs@柱）相比，GO/SiO₂ NPs@柱具有最高的分离度。GO/SiO₂ NPs@柱用于分离蛋清，酸性和碱性蛋白质以及三种卵清蛋白糖异构体在36分钟内单次运行中被分离。通过计算开管毛细管电色谱中萘和联苯保留时间的相对标准偏差（RSD）来评估日内、日间和柱间重现性。发现RSD值小于7.1%。
