Fabrication and evaluation of sulfanilamide-imprinted composite sensors by developing a custom-tailored strategy

In this paper, we have presented a custom-tailored strategy to fabricate molecularly imprinted composite sensors (MIPs/QDs@SiO 2 ) with highly selective recognition ability for the determination of sulfanilamides (SAs). The modified SiO 2 sphere, modified QDs, acrylamide (AM), and ethyl glycol dimethacrylate (EGDMA) were used as the supporter, the fluorescent material, the functional monomer , and the cross-linker, respectively. Afterward, a two-step imprinting polymerization reaction was implemented to fabricate the novel sensor MIPs/QDs@SiO 2 . Attributing to the SiO 2 with the surface functional monomer and the QDs with functional group, SAs molecules are attracted to the QDs and bound to the SiO 2 surface, hence accelerating the growth of homogeneous recognition sites on the surface of SiO 2 and guaranteeing the distance between the recognition sites and the QDs. After the experimental conditions were optimized, such fluorescence sensors can be used for well selective detection of SAs with a linear range of 2.0–30   μmol/L and a limit of detection is 0.17   μmol/L. Most importantly, the MIPs/QDs@SiO 2 can be successfully applied to the determination of SAs in real river water, which demonstrate high selectivity and stability and offer a promising platform for detecting environmental pollutants.