A tailored molecular imprinting ratiometric fluorescent sensor based on red/blue carbon dots for ultrasensitive tetracycline detection

The molecular imprinting ratiometric fluorescence sensor has exhibited great potential in biological and environmental detection because of the combination between the excellent selectivity of molecular imprinting technique and outstanding robustness of ratiometric measurement methods On this basis, two kinds of different well-resolved wavelengths and high-fluorescent carbon dots (CDs) were prepared by various solvent extraction using osmanthus fragrans leaves as carbon source. Then the ratiometric fluorescence sensor (MIPs@rCDs/bCDs@SiO₂) has been constructed by the obtained CDs which the red-emission CDs (rCDs) were used to responsive signal and the blue-emission CDs (bCDs) was served as reference signal and applied for highly selective and excellent sensitive detection of tetracycline (TC). Under optimum conditions, the ratiometric fluorescence MIPs@rCDs/bCDs@SiO₂ sensor has also exhibited lower detection limit of 1.19 nM and the linear range of 0–50 nM. The ratiometric fluorescence sensor was further successfully employed to the determination of TC in water samples gathered from local river water and tap water, indicating its great worth toward water sample analysis in complicated environments.