A novel fluorescent sensor based on a magnetic covalent organic framework-supported, carbon dot-embedded molecularly imprinted composite for the specific optosensing of bisphenol A in foods

An efficient one-pot strategy for the synthesis of a bisphenol A (BPA) fluorescent sensor based on a magnetic covalent organic framework-supported, carbon dot-embedded molecularly imprinted composite (named [email protected]@MIP) is reported for the first time in this work. Herein, MCOFs were prepared via the simple in-situ growth of COF crystals on Fe3O4 nanoparticles and acted as supports to provide a large surface area for CD-embedded MIP layer deposition through a room temperature sol-gel molecular imprinting process. The fabricated [email protected]@MIP integrated the useful magnetic properties of Fe3O4, the signal transduction function of CDs, the signal amplification effect derived from the COFs and MIP, and the specific recognition behavior of MIP toward template molecule BPA. Based on the fluorescence quenching behavior of BPA for the [email protected]@MIP, a highly sensitive and selective fluorescent [email protected]@MIP sensor was developed over the concentration range of 25–3000 μg L-1 with a low detection limit (12 μg L-1). Furthermore, the [email protected]@MIP sensor was employed to detect BPA in canned goods and boxed drinks with satisfactory results, which agreed well with those obtained by the traditional high performance liquid chromatography (HPLC) method, demonstrating the good reliability, accuracy and practicality of our constructed sensor.