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Highly selective enrichment of phosphopeptides by on‐chip indium oxide functionalized magnetic nanoparticles coupled with MALDI‐TOF MS
Author(s) -
Jiang Dandan,
Song Naizhong,
Li Xiqian,
Ma Jiutong,
Jia Qiong
Publication year - 2017
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.201700213
Subject(s) - chemistry , chromatography , detection limit , magnetic nanoparticles , adsorption , selectivity , nanoparticle , magnetic separation , materials science , nanotechnology , organic chemistry , metallurgy , catalysis
Selective and efficient preconcentration is indispensable for low concentration of phosphopeptides in phosphorylated protein‐related samples prior to MS‐based analysis. Herein, an on‐chip system coupled magnetic SPE with MALDI‐TOF MS was designed. A metal oxide affinity chromatography material, indium oxide, was coated on the surface of Fe 3 O 4 magnetic nanoparticles to prepare the adsorbent, spatially confined with an applied magnetic field. The adsorbent exhibited high selectivity for phosphopeptides in tryptic digests of the mixture of β ‐casein and BSA (1:1000) and the mixture of β ‐casein, BSA, and ovalbumin (1:100:100). Thanking to the enrichment ability and specificity for phosphopeptides with the adsorbent, the on‐chip magnetic SPE‐MALDI‐TOF MS approach showed high sensitivity with a low detection limit of 4 fmol. In addition, the developed approach was used to analyze phosphopetides in non‐fat milk digests and human serum successfully.