Evolution of Aptamer Materials Maps Exosomal Surface Proteins at the Nano–Bio Interface

Exosomes are nanoscale extracellular vesicles whose membrane-embedded proteins encode phenotypic information but remain difficult to interrogate due to hydrophobicity, low copy number, and nanoscale curvature. Here, we present AptEx-ID, a chemically guided aptamer evolution strategy that enables direct discovery and quantification of exosomal membrane proteins under native conditions. By introducing indole-modified nucleotides to emulate aromatic amino acid side chains, AptEx-ID expands the mole