A fluorescence sensor based on surface functionalization and heteroatom co-doped carbon dots for detection of tetracycline

Tetracycline (TC), as a budget broad-spectrum antibiotic, its wide-ranging use might result in residues being left in the environment and existed potential harm. Hence, we designed a ratiometric fluorescence probe (N,P@CDs@Eu) based on Eu functionalized nitrogen and phosphorus elements in-situ self-doping carbon dots (CDs) for detection of TC. The N,P@CDs was synthesized utilizing adenosine triphosphate (ATP) contained a significant amount of phosphate groups. These phosphate groups served as binding sites for Eu, facilitating functionalization of N,P@CDs to form the N,P@CDs@Eu. Under ultraviolet irradiation, N,P@CDs@Eu only exhibited the intense emission at 440 nm. However, during the sensing process, TC quenched the fluorescence at 440 nm of via inner filter effect (IFE), and induced N,P@CDs@Eu to exhibited fluorescence at 617 nm through antenna effect (AE). So that, a ratiometric fluorescence sensor for detection of TC had been constructed, which could achieve quantitative determination within 0.1–50 μM range, the detection limit of 22.6 nM. Moreover, N,P@CDs@Eu exhibited outstanding detection capabilities of TC in milk and tap water, with high recovery rates (99.47 %–108.12 %) and low errors (R < 4.68 %), indicating N,P@CDs@Eu had enormous application prospects in the field of food safety and environmental detection.