Ultrasensitive and Highly Selective Detection of Bisphenol a Using Core-Shell Magnetic Molecularly Imprinted Quantum...

The main aim of this work was to develop a magnetic molecularly imprinted polymer (MMIP)-based quantum dots electrochemiluminescent (ECL) probe for the ultrasensitive and highly selective detection of bisphenol A (BPA). The prepared core-shell Fe₃O₄@SiO₂ exhibited superparamagnetic properties, making them easy to separate. The MIP was fabricated by the self-polymerization of dopamine on the surface of amine-terminated Fe₃O₄@SiO₂ (Fe₃O₄@SiO₂-NH₂) magnetic nanoparticles and doped with quantum dots (QDs) to form an ECL system. The ECL intensity decrease with the concentration of BPA increased, due to the BPA molecules occupied molecularly imprinted sites and blocked the strong ECL emission of QDs. The prepared ECL sensor performed satisfactorily in the detection of BPA, with a wide linear range from 10^- 4 to 10^- 9 mol L^- 1 and a low detection limit of 3.4 × 10^- 10 mol L^- 1 (S/N = 3). The recoveries of BPA achieved were in the range 96%-107% in the detection of actual water samples. The proposed ECL sensor displayed high sensitivity and stability, and may provide an approach for determining other important analytes.