Template-free synthesis of uniform mesoporous SnO sub(2) nanospheres for efficient phosphopeptide enrichment

A one-step and template-free method to prepare uniform SnO sub(2) nanospheres with a mesoporous structure was developed for the applications in phosphopeptide enrichment. The as-synthesized mesoporous SnO sub(2) nanospheres have a large surface area and highly active surfaces for the effective binding of phosphopeptides. Compared with the non-porous SnO sub(2) and commercial TiO sub(2), mesoporous SnO sub(2) 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 SnO sub(2) nanospheres promising in further phosphoproteomic research.