A green facile method was developed to synthesize the carbon quantum dots from barberry, a native plant, as a new carbon source. The synthesis strategy is a simple one-step hydrothermal process without requiring hazardous chemical reagents. The spherical structure of b-CDs with an average particle size of 3.3 nm including oxygen and nitrogen functional groups was evaluated by various analyses (FT-IR, DLS, XRD, FE-SEM, TEM, AFM). The synthesized b-CDs with QY of 12.82 % were used as a fluorescence optical probe (λ