“…15 However, capping agents can also be used to harness and control chemical reactions on their surface. 16 For example, CdS QDs capped with thiols, nitroxides, and surfactants can be used to detect peptides, tyrosine, cysteine, and organic radicals. 17,18 In addition, QDs capped with biodegradable, biocompatible, and compounds with low toxicity from bacteria 19 or plant leaves 20 have been used to supress the growth of A549 lung cancer cell.…”