Hsu, P.-C.P.-C.HsuChen, P.-C.P.-C.ChenOu, C.-M.C.-M.OuChang, H.-Y.H.-Y.ChangHUAN-TSUNG CHANG2018-09-102018-09-102013http://www.scopus.com/inward/record.url?eid=2-s2.0-84874834789&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/381019Highly water-soluble, biocompatible, and photoluminescent carbon nanodots (C-dots) having an average diameter 3.4 ± 0.8 nm and a quantum yield 4.3% are obtained from used green tea through grinding, calcination and centrifugation. The as-prepared C-dots are stable in high-ionic-strength media (e.g. 500 mM NaCl) and under light irradiation, allowing images of MCF-10A, MCF-7 and MDA-MB-231 cells to be recorded. The C-dots are mostly localized in the cell membranes and cytoplasms, with evidence of excitation-wavelength cell images. Relative to catechin, the C-dots provide greater inhibition efficiency of the growth of MCF-7 and MDA-MB-231 cancer cells, with lower toxicity for the MCF-10A normal cells. The inhibitory activity of C-dots is associated with the generation of greater amounts of reactive oxygen species. A prothrombin time (PT) assay of plasma samples reveals excellent biocompatibility of the C-dots. To the best of our knowledge, for the first time the C-dots provide inhibition efficiencies up to 80% and 82% for MCF-7 and MDA-MB-231 cancer cells, respectively, showing their high potential as cancer inhibitors. ? The Royal Society of Chemistry 2013.[SDGs]SDG3[SDGs]SDG6Average diameter; Inhibition activity; Inhibition efficiency; Inhibitory activity; Light irradiations; Mda-mb-231 cells; Prothrombin time; Reactive oxygen species; Biocompatibility; Calcination; Cell membranes; Centrifugation; Cytology; Ionic strength; Carbonjournal article10.1039/c3tb00545c2-s2.0-84874834789WOS:000315722500001