After obtaining a stable CDs photocatalyst with an appropriate redox window, we investigated its compatibility with radical-mediated C(sp 3 )-H functionalization reactions. Alkyl anilines were selected as C-H substrates in this proof-of-concept study. In our proposed reaction mechanism (Fig. ), the hydrogen atom of α-amino C-H bond is abstracted by photo-generated thiyl radical (S-H, BDE = 87 kcal/mol) (ref ), generating a highly nucleophilic α-amino radical, which should be further captured by electron deficient alkenes (ref . Besides, nitrogen-containing molecules are prevalent and important in natural products and pharmaceutical compounds.