Characterization of the adsorption of oligonucleotides on mercaptopropionic acid-coated CdSe/ZnS quantum dots using fluorescence resonance energy transfer

► Oligonucleotides adsorb on quantum dots coated with mercaptopropionic acid (MPA). ► Adsorption driven by dipolar interactions between neutral MPA ligands and nucleobases. ► The extent of adsorption depends on oligonucleotide sequence composition and length. ► The extent of adsorption depends on the degree of ionization of the MPA ligands. ► Adsorption can be manipulated by adjusting pH and ionic strength.