title: Tailor-made magnetic Fe3O4@mTiO2 microspheres with a tunable mesoporous anatase shell for highly selective and effective enrichment of phosphopeptides.
abstract: Selective enrichment of phosphoproteins or phosphopeptides from complex mixtures is essential for MS-based phosphoproteomics, but still remains a challenge. In this article, we described an unprecedented approach to synthesize magnetic mesoporous Fe(3)O(4)@mTiO(2) microspheres with a well-defined core/shell structure, a pure and highly crystalline TiO(2) layer, high specific surface area (167.1 m(2)/g), large pore volume (0.45 cm(3)/g), appropriate and tunable pore size (8.6-16.4 nm), and high magnetic susceptibility. We investigated the applicability of Fe(3)O(4)@mTiO(2) microspheres in a study of the selective enrichment of phosphopeptides. The experiment results demonstrated that the Fe(3)O(4)@mTiO(2) possessed remarkable selectivity for phosphopeptides even at a very low molar ratio of phosphopeptides/non-phosphopeptides (1:1000), large enrichment capacity (as high as 225 mg/g, over 10 times as that of the Fe(3)O(4)@TiO(2) microspheres), extreme sensitivity (the detection limit was at the fmol level), excellent speed (the enrichment can be completed in less than 5 min), and high recovery of phosphopeptides (as high as 93%). In addition, the high magnetic susceptibility allowed convenient separation of the target peptides by magnetic separation. These outstanding features give the Fe(3)O(4)@mTiO(2) composite microspheres high benefit for mass spectrometric analysis of phosphopeptides.
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Wan-Fu
authors.initials: WF
authors.lastname: Ma
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lu-Lu
authors.initials: LL
authors.lastname: Li
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: You
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Zhang
authors.forename: Ju-Mei
authors.initials: JM
authors.lastname: Li
authors.forename: Meng
authors.initials: M
authors.lastname: Yu
authors.forename: Jia
authors.initials: J
authors.lastname: Guo
authors.forename: Hao-Jie
authors.initials: HJ
authors.lastname: Lu
authors.forename: Chang-Chun
authors.initials: CC
authors.lastname: Wang
mesh_terms: D052203:Ferrosoferric Oxide / Q000737:chemistry*; D008863:Microspheres; D036103:Nanotechnology / Q000379:methods*; D010748:Phosphopeptides / Q000737:chemistry*; D016062:Porosity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014025:Titanium / Q000737:chemistry*
chemical_list: D010748:Phosphopeptides; C009495:titanium dioxide; D014025:Titanium; D052203:Ferrosoferric Oxide