Single‐chain nanoparticles can be obtained via single‐chain folding assisted by intramolecular crosslinking reversibly or irreversibly. Single‐chain folding is also an efficient route to simulate biomacromolecules. In present study, poly(N‐hydroxyethylacrylamide‐co‐4′‐(propoxy urethane ethyl acrylate)‐2,2′:6′,2″‐terpyridine) (P(HEAm‐co‐EMA‐Tpy)) is synthesized via reversible addition fragmentation chain transfer polymerization. Single‐chain folding and intramolecular crosslinking of P(HEAm‐co‐EMA‐Tpy) are achieved via metal coordination chemistry. The intramolecular interaction is characterized on ultraviolet/visible spectrophotometer (UV–vis spectroscopy), proton nuclear magnetic resonance (1H NMR), and differential scanning calorimetry (DSC). The supramolecular crosslinking mediated by Fe2+ plays an important role in the intramolecular collapsing of the single‐chain and the formation of the nanoparticles. The size and morphology of the nanoparticles can be controlled reversibly via metal coordination chemistry, which can be characterized by dynamic light scattering (DLS), transmission electron microscope (TEM), and atomic force microscope (AFM).
An ionic liquid-modified molecularly imprinted polymer (IL-MIP) composite with sulfamethazine as a template molecule and methyl acrylic acid and 1-aminopropyl-3-methylimidazolium bromide as functional monomers was successfully synthesized. The achieved IL-MIP was characterized and evaluated in detail and utilized in the extraction and cleanup of sulfonamides (SAs) in poultry egg samples. The results demonstrated that the IL-MIP possessed a broad reorganization toward SAs and could selectively adsorb 21 kinds of SA compounds. Furthermore, the solid-phase extraction column based on the IL-MIP was used in the extraction and cleanup of 21 SAs in eggs, and the confirmatory detection of SAs was performed using ultraperformance liquid chromatography–tandem mass spectrometry. Under optimum conditions, the limits of detection (LODs) for all SAs ranged from 0.1 ng·g−1 to 1.5 ng·g−1, and the LOD of this method was better than those of the existing methods. The recoveries of SA compounds spiked in egg samples ranged from 84.3% to 105.8%, with low relative standard deviations (<15%). The developed method based on the IL-MIP extraction and cleanup was successfully used in the detection of 21 SAs in more than 100 real poultry egg samples. The results indicated that the proposed method was suitable for detecting 21 SAs in poultry eggs. 相似文献