Hydrothermal synthesis of α-Fe2O3@SnO2 core–shell nanotubes for highly selective enrichment of phosphopeptides for mass spectrometry analysis

Abstract

In this work, we synthesized α-Fe₂O₃@SnO₂ 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. SnO₂ nanoparticles with an average crystallite size of around 5 nm form a layer of about 10 nm on both walls of the α-Fe₂O₃ nanotubes. To demonstrate their ability for selective enrichment of phosphopeptides, we applied α-Fe₂O₃@SnO₂ 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 SnO₂ coated α-Fe₂O₃ nanotubes show excellent potential for selective enrichment of phosphopeptides.