Du Zhuo, Yu Yong-Liang, Yan Xiao-Rui, Wang Jian-Hua
Research Center for Analytical Sciences, Box 332, Northeastern University, Shenyang 110004, China.
Analyst. 2008 Oct;133(10):1373-9. doi: 10.1039/b804347g. Epub 2008 Jul 11.
Multi-walled carbon nanotubes (MWNTs) were assembled on a silica surface using a polyelectrolyte-assisted layer-by-layer (LBL) assembly technique. The surface-assembled silica spheres with MWNTs (MWNTs/SiO(2)), which serve as a novel solid-phase extraction sorbent for separation/pre-concentration of basic proteins, was investigated. The adsorption behavior of cytochrome c (cyto-c) by MWNTs/SiO(2) spheres agrees well with the Langmuir adsorption model. A thorough scrutiny of the experimental parameters affecting the adsorption of cyto-c from aqueous solution onto the MWNTs/SiO(2) spheres and its subsequent desorption was carried out. A maximum adsorption capacity of cyto-c was derived as 112 mg (cyto-c) g(-1) (MWNTs). A distinct feature of the MWNTs/SiO(2)-packed micro-column provides clear advantages of minimized flow impedance when operated in a flow system, in addition to better separation efficiency as well as the favorable enrichment capability of proteins, characterized by an enrichment factor of 30 by using 2.0 mL of aqueous solution. The practical applicability of the MWNTs/SiO(2) spheres as a sorbent for the isolation of basic proteins from acidic protein species was demonstrated by effective separation of cyto-c from bovine serum albumin (BSA).
采用聚电解质辅助层层组装技术将多壁碳纳米管（MWNTs）组装在二氧化硅表面。研究了表面组装有MWNTs的二氧化硅球（MWNTs/SiO₂），它作为一种新型固相萃取吸附剂用于碱性蛋白质的分离/预富集。MWNTs/SiO₂球对细胞色素c（cyto-c）的吸附行为与朗缪尔吸附模型吻合良好。对影响cyto-c从水溶液吸附到MWNTs/SiO₂球上及其后续解吸的实验参数进行了深入研究。得出cyto-c的最大吸附容量为112 mg（cyto-c）g⁻¹（MWNTs）。MWNTs/SiO₂填充微柱的一个显著特点是，在流动系统中运行时，除了具有更好的分离效率以及对蛋白质的良好富集能力（使用2.0 mL水溶液时富集因子为30）外，还具有最小化流动阻抗的明显优势。通过从牛血清白蛋白（BSA）中有效分离cyto-c，证明了MWNTs/SiO₂球作为从酸性蛋白质物种中分离碱性蛋白质的吸附剂的实际适用性。
