Enhanced specificity of bimetallic ions via mesoporous confinement for phosphopeptides in human saliva

Phosphopeptides were of great significance in disease diagnosis and monitoring its dynamic changes. In this article, we proposed a more efficient method to synthesize a kind of bimetallic mesoporous silica nanomaterials (Fe₃O₄@mSiO₂-PO₃-Ti⁴⁺/Zr⁴⁺) and applied it to the analysis of phosphopeptides in human saliva samples based on IMAC technology. The chelation group was introduced into mesopores at the same time as the formation of mesoporous silica which significantly reduced the synthesis procedure and improved the synthesis efficiency. The as-prepared materials showed great sensitivity, selectivity and size-exclusion performance for phosphopeptides in standard β-casein digests. More importantly, the materials identified 85 phosphopeptides in disease saliva samples which provided a candidate choice in future clinical examination.