Hydrophilic modification of silica-titania mesoporous materials as restricted-access matrix adsorbents for enrichment of phosphopeptides

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• 作者：Fei Wang^a ; Yafeng Guan^b ; Sen Zhang^c ; Yan Xia^a ; ^{nkxiayan@nankai.edu.cn}
• 关键词：Restricted-access matrix (RAM) adsorbents ; Mesoporous materials (Ti-MCM-41) ; Hydrophilic Modification ; Phosphopeptide enrichment ; Tryptic digestion
• 刊名：Journal of Chromatography A
• 出版年：2012
• 期刊代码：47_00219673
• 类别：ch
• 出版时间：13 July, 2012
• 卷：1246
• 期：Complete
• 页码：76-83
• 文件大小：2148 K

摘要

A new nano-scale restricted-access matrix (RAM) SiO₂ (MCM-41) with relatively high Ti-content (Ti/Si = 0.1), but superior surface area (1129 m²/g), was successfully synthesised for the enrichment of phosphopeptides. The TiO₂ was incorporated into the Si-MCM-41 via a hydrothermal process and the external surface was modified with alkyl diol by the successive hydrolysis of 纬-(glycidyloxypropyl) trimethoxysilane (GPTMS). Scanning electron microscopy, transmission electron microscopy, N₂ adsorption and Fourier transform infrared spectroscopy were used to characterise the alkyl diol-Ti-MCM-41. The appropriate pore diameter (2 nm) coupled to the marshy weeds-like hydrophilic external surface result in an efficient size-exclusion effect for the adsorption of standard cytochrome c with a molecular weight (MW) of ca. 12.4 kDa. At the same time, the strong affinity interaction between the incorporated titanium in the framework and the phosphoryl groups of phosphopeptides demonstrated a selective extract of phosphopeptides from the tryptic digestion. The detection sensitivity for phosphopeptides, determined by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) was as low as 5 fmol for standard tryptic digest of 尾-casein. Therefore, this alkyl diol-Ti-MCM-41 mesoporous material can be used as a potential adsorbent for applications in MS-based phosphoproteomics.