One-pot synthesis of hydroxypropyl-β-cyclodextrin capped fluorescent sulfur quantum dots for highly sensitive and selective recognition of tartrazine

Sulfur quantum dots (SQDs), the rising star in fluorescent nanomaterials, have captured increasing attention due to their unique attributes. However, the development of SQDs with targeted fluorescence response to analyte is still a challenge. Herein, we report a robust fluorescent SQDs material that possess both molecular recognition and fluorescence detection capability by employing hydroxypropyl-β-cyclodextrin (HP-β-CD) as ligand. The prepared SQDs simultaneously display fine aqueous dispersibility, stable and tunable fluorescence, and favorable biocompatibility, which enable them promising for applications in cellular imaging and sensing. Owing to the synergistic effect of inner filter effect (IFE) and host-guest interaction, the SQDs can be utilized as an effective fluorescent probe for tartrazine (TTZ) detection with excellent sensitivity and selectivity. The limit of detection can reach 82 nM with a wide linear range of 0–30 μM. Furthermore, the fluorescent SQDs were successfully utilized to detect TTZ in river water and food samples with satisfactory performance.