Molecularly imprinted ratiometric fluorescence sensor for visual detection of 17β-estradiol in milk: A generalized strategy toward imprinted ratiometric fluorescence construction

17β-Estradiol (E2) is the typical endocrine disruptor of steroidal estrogens and is widely used in animal husbandry and dairy processing. In the environment, even lower concentrations of E2 can cause endocrine dysfunction in organisms. Herein, we have developed a novel molecularly imprinted ratiometric fluorescent sensor based on SiO 2 -coated CdTe quantum dots (CdTe@SiO 2 ) and 7-hydroxycoumarin with a post-imprint mixing strategy. The sensor selectively detected E2 in aqueous environments due to its two fluorescent signals with a self-correction function. The sensor has been successfully used for spiking a wide range of real water and milk samples. The results showed that the sensor exhibited good linearity over the concentration range 0.011–50 μg/L, obtaining satisfactory recoveries of 92.4–110.6% with precisions (RSD)