Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai 200237, China.
Nanoscale. 2013 Nov 21;5(22):10936-44. doi: 10.1039/c3nr02932h. Epub 2013 Sep 23.
Magnetic mesoporous carbon microspheres with a yolk-shell structure (YSMMCS) have been prepared via a new in situ carbon source strategy. The material was fabricated by two shells coated onto the Fe3O4 particles; the inner dense and thick silica shell could protect the magnetic core from harsh acidic solvents as well as induce the void between the core and the outer shell for the yolk-shell structure, while the outer organosilica shell was used as the template and carbon source for in situ preparation of a carbon shell with mesoporous structure. A C18-alkyl chain was incorporated in situ as the carbon precursor efficiently, avoiding the conventional infiltration step, which was very difficult to manipulate and time-consuming with the possibility of losing the carbon precursor. The resulting yolk-shell magnetic mesoporous carbon microspheres exhibited a high surface area (273.15 m(2) g(-1)), a large pore volume (0.31 cm(3) g(-1)), and a strong magnetic response (a saturation magnetization value of 34.57 emu g(-1)). As a result of the void between the core and the outer shell and the π-π stacking effect, adsorption capacity reached 191.64 mg g(-1) by using Rhodamine B as a standard analyte, indicating the great potential application of the material as drug carriers. Owing to the inherent hydrophobicity and high surface area, the composite material showed better performance in the enrichment of peptides than a magnetic mesoporous silica material (Fe2O3@nSiO2@mSiO2). According to the LC-MS/MS results, about 51 and 29 nonredundant peptides were identified from tryptic digests of 5 nM BSA. Additionally, taking advantage of the mesoporous structure and strong magnetic response, the material was utilized to selectively extract low abundance endogenous peptides from human serum in the presence of high abundance proteins. Based on the LC-MS/MS results, 962 endogenous peptides were obtained by 2.5 mg YSMMCS relative to 539 endogenous peptides by 5 mg Fe2O3@nSiO2@mSiO2, confirming the outstanding performance of YSMMCS in peptidome analysis.
介孔碳微球具有蛋黄-壳结构（YSMMCS）通过一种新的原位碳源策略制备。该材料由涂覆在 Fe3O4 颗粒上的两层壳组成；内层致密而厚的二氧化硅壳可以保护磁性核免受苛刻的酸性溶剂的影响，并诱导核与外壳之间的空隙形成蛋黄-壳结构，而外层有机硅壳则用作模板和原位制备介孔结构碳壳的碳源。C18-烷基链作为碳前体被原位有效地掺入，避免了传统的渗透步骤，该步骤非常难以操作，耗时且有可能失去碳前体。所得的蛋黄-壳磁性介孔碳微球具有高比表面积（273.15 m2 g-1），大孔体积（0.31 cm3 g-1）和强磁响应（饱和磁化强度值为 34.57 emu g-1）。由于核与外壳之间的空隙和π-π堆积效应，以罗丹明 B 为标准分析物，吸附量达到 191.64 mg g-1，表明该材料作为药物载体具有巨大的潜在应用价值。由于固有疏水性和高比表面积，与磁性介孔硅材料（Fe2O3@nSiO2@mSiO2）相比，复合材料在肽的富集中表现出更好的性能。根据 LC-MS/MS 结果，从 5 nM BSA 的胰蛋白酶消化物中鉴定出约 51 个和 29 个非冗余肽。此外，利用介孔结构和强磁响应，该材料在存在高丰度蛋白质的情况下，从人血清中选择性地提取低丰度内源性肽。根据 LC-MS/MS 结果，与 5 mg Fe2O3@nSiO2@mSiO2 相比，YSMMCS 获得了 962 种内源性肽，而 5 mg Fe2O3@nSiO2@mSiO2 仅获得 539 种内源性肽，证实了 YSMMCS 在肽组学分析中的出色性能。
