Rapid isolation and proteome analysis of urinary exosome based on double interactions of Fe₃O₄@TiO₂-DNA aptamer

There are accumulating evidence that proteins carried by exosomes in urine are most possibly used as biomarkers or therapeutic carriers for certain diseases. The isolation of exosomes is therefore highly desirable for aiding the downstream protein analysis. Particularly, urine is a dynamic biological fluid changing within a short time, resulting in that the separation of urinary exosome requires more efficient technology. Here, a new biocompatible material (denoted as Fe₃O₄@TiO₂-CD63 aptamer) is designed and synthesized for rapid exosome isolation from human urine, depending on the double interactions of TiO₂ with phosphate groups as well as aptamers with specific exosome proteins. Moreover, within 10 min, 92.6% exosomes with intact structure are captured from urine by Fe₃O₄@TiO₂-CD63 aptamers, from which 999 proteins are detected through LC-MS/MS.