Hydrothermal synthesis of α-Fe(2)O(3)@SnO(2) core-shell nanotubes for highly selective enrichment of phosphopeptides for mass spectrometry analysis.

In this work, we synthesized α-Fe(2)O(3)@SnO(2) core-shell structure nanotubes by a facile two-step hydrothermal method for selective enrichment of phosphopeptides. The core-shell structure nanotubes were found to have outer diameters of 90-110 nm, thicknesses of 30 nm, and lengths of 260-280 nm. SnO(2) nanoparticles with an average crystallite size of around 5 nm form a layer of about 10 nm on both walls of the α-Fe(2)O(3) nanotubes. To demonstrate their ability for selective enrichment of phosphopeptides, we applied α-Fe(2)O(3)@SnO(2) nanotubes to the isolation and enrichment of the phosphopeptides from standard protein digestion and real samples. The enriched peptides were analyzed by MALDI-MS and LC-ESI MS. Experiment results demonstrate that SnO(2) coated α-Fe(2)O(3) nanotubes show excellent potential for selective enrichment of phosphopeptides.