Template-free synthesis of uniform mesoporous SnO₂ nanospheres for efficient phosphopeptide enrichment

A one-step and template-free method to prepare uniform SnO₂ nanospheres with a mesoporous structure was developed for the applications in phosphopeptide enrichment. The as-synthesized mesoporous SnO₂ nanospheres have a large surface area and highly active surfaces for the effective binding of phosphopeptides. Compared with the non-porous SnO₂ and commercial TiO₂, mesoporous SnO₂ nanospheres represent superior performance in the specific trapping of phosphopeptides from both standard protein and complex nonfat milk digests for mass spectrometry-based phosphoproteomic analysis. The feasible synthetic approach and the excellent enrichment performance make the mesoporous SnO₂ nanospheres promising in further phosphoproteomic research.