Detection of nonfluorescent cyhalothrin in honey by a spheral SiO2-based particle coating with thin fluorescent molecularly imprinted polymers film

Abstract

In this study, we report a general protocol for making core–shell SiO₂@KH570-MIP based on the surface modification of SiO₂ beads for the selective detection of ultra trace cyhalothrin. We first prepared the fluorescent surface molecularly imprinted polymer (SMIP) spheres via copolymerization of acrylamide with allyl fluorescein in the presence of cyhalothrin to form recognition sites. The experimental results showed that the fluorescence quenching of SiO₂@KH570-MIP for cyhalothrin was much higher than that of the structural analogue composite, which illustrated good recognition capacity and selectivity of SiO₂@KH570-MIP for the template. In addition, a linear relationship could be obtained at a lower concentration range of 0–2.5 nM with a correlation coefficient of 0.99698 described by the Stern–Volmer equation. The results of practical detection suggest that the developed method satisfactorily determines cyhalothrin in honey samples. This study therefore demonstrated the potential of SiO₂-based SMIP spheres for the recognition and detection of cyhalothrin in food.