Synthesis, biocompatibility and luminescence properties of quantum dots conjugated with amino acid-functionalized β-cyclodextrin

► Amino acid-modified β-CD-coated QDs were prepared by a simple ultrasonic method. ► Amino acid-modified β-CD-coated QDs have appropriate size, high colloidal stability and strong optical emission properties. ► In vitro cytotoxicity is lower in ECV-304, SH-SY5Y and HeLa cells. ► The positive charge of amino acid resulted in a considerable increase in biocompatibility of QDs.