Hydrothermal synthesis of bright blue-emitting carbon dots for bioimaging and fluorescent determination of baicalein

Abstract Bright blue-emitting CDs (B-CDs) with a considerable QY of 66 % were synthesized from precursors of cysteine, trisodium citrate dehydrate and ethylenediamine by a simple hydrothermal method. Excellent luminescence stability with various pH, salt concentrations, storage time and UV radiation time is found with excitation-independent emission. Based on the good biocompatibility, B-CDs was successfully used for fluorescence imaging of human ovarian cancer cells. Moreover, the B-CDs were confirmed to be capable of baicalein sensing with a good linear relationship in range of 0–30 μM and the limit of detection of 33 nM. The corresponding sensing mechanism was proved to be fluorescence internal filtration effect and the static quenching effect. All results demonstrate that the B-CDs have good potential of the versatile utilization in biology-relevant fields.