Eu doped Ti3C2 quantum dots to form a ratiometric fluorescence platform for visual and quantitative point-of-care testing of tetracycline derivatives

Antibiotic residues have become a public health issues, the fast detection of tetracycline (Tc) in the environment is urgently required. In this work, Ti3C2 quantum dots (Ti3C2 QDs) and Europium ions jointly constructed a ratiometric fluorescence (FL) platform for the detection of Tc, based on synergistic impact of the Foster Resonance Energy Transfer (FRET) from Ti3C2 QDs to Eu3+ ions and the Antenna Effect (AE) between Tc and Eu3+ ions. And we proposed a ratiometric FL platform for detecting Tc with good linear response range (100-1000 uM) and low detection limit (48.79 nM). Meanwhile, we applied this platform to detect a serious of β-diketone ligands of Eu3+ ions, demonstrating the platform's versatility for this category of chemical. Furthermore, based on the color changes of QDs@Eu3+ from blue to red at 365 nm ultraviolet light, an intelligent detection smart device was built for the visual semi-quantitative detection of Tc in actual samples. We proved the applicability of the device in complicated samples and the potential for rapid, sensitive, intuitive and point-of-care detection in the field of environment, food, pharmaceutical and agriculture.