The present disclosure relates to a plurality of quantum dot nanoparticles conjugated to ligands, and in particular a plurality of quantum dot nanoparticles wherein each nanoparticle is conjugated to an exosome-specific binding ligand. The present disclosure also relates to methods of making such a plurality of conjugated quantum dot nanoparticles, methods of detecting exosomes using such a plurality of conjugated quantum dot nanoparticles and methods of detecting exosomes using such a plurality of conjugated quantum dot nanoparticles.
