Europium Doped Silicon Quantum Dot As a Novel FRET Based Dual Detection Probe: Sensitive Detection of Tetracycline, Zinc, and Cadmium.

The imbalance of Zn 2+ /Cd 2+ in the human body can lead to many serious diseases due to the overuse of antibiotics and deposition in animal products. Developing a functional material for detecting is challenging and in demand. Herein, silicon quantum dots (SiQDs) are designed as a functional platform for the detection of tetracycline and Zn 2+ /Cd 2+ . The COOH functionalized SiQDs with the emission wavelength of 450 nm are chelated with Eu(NO 3 ) 3 to form SiQDs-Eu 3+ ratio fluorescent probes, which can be used to detect tetracycline (TCs) and Zn 2+ /Cd 2+ by fluorescence resonance energy transfer (FRET) principle sequentially. The fluorescent probe showed good linearity between ion concentration and fluorescence enhancement. The detection limit of TCs and Zn 2+ /Cd 2+ are 0.2 × 10 -6  m and 3 × 10 -6  m, respectively, when the pH of the solution is 7.4. In addition, the synthesized SiQDs-Eu 3+ exhibited good stability (from 94.9% to 103.1%). The relative standard deviations (RSD, n = 10) of human serum and urine were both less than 3%. Therefore, the SiQDs-Eu 3+ ratio fluorescence probe will provide a good application prospect in actual sample detection.