In summary, we have creatively synthesized CDs originated from rose flowers according to a simple and green approach. Significantly, the CDs prepared here were applied as a biosensor for the quantification of TC on the basis of TC induced fluorescence quenching of CDs. This mechanism was presumably explained by the interactions between the surface groups of CD sand TC. And these interactions contributed to the energy of CDs captured by forming new bonds [32], thus facilitating to quench the fluorescence of CDs. Interestingly, the new type of CDs was employed for fluorescent staining, demonstrating their possibility to broaden avenues in biosensing and other purpose.