Preparation of an epinephrine-oriented imprinted coating on silica nanoparticles for rapid, facile and selective extraction and determination of epinephrine from animal-derived foods

Abstract

Epinephrine (EP) is present in mammals and contains a cis-diol, which is a key biological neurotransmitter of catecholamines. It is necessary to develop a facile, fast and sensitive detection method to rationally regulate and monitor the residues of EP in animal-derived foods. However, the low content of EP and high content of complex interfering substances pose difficulties and challenges for direct determination of EP. Therefore, efficient sample preparation prior to detection becomes necessary. In this work, boronate affinity-based oriented surface imprinting was used in the preparation of EP-imprinted silica nanoparticles (SiO₂@APTES@FFPBA@MIPs). Silica nanoparticles and boronic acid ligand 3-fluoro-4-formylphenylboronic acid (FFPBA) were used as the supporting material and functional monomer, respectively. 2-Anilinoethanol was homopolymerized on the surface of FFPBA-functionalized silica nanoparticles (SiO₂@APTES@FFPBA) to form an imprinting coating with appropriate thickness. The prepared SiO₂@APTES@FFPBA@MIPs exhibited good specificity, excellent binding ability (30.50 mg g⁻¹), fast kinetics (7 min), and low binding pH (pH 5.0) toward EP. The Q_max and K_d values of SiO₂@APTES@FFPBA@MIPs were estimated to be 30.50 ± 0.16 mg g⁻¹ and 8.84 ± 0.62 × 10⁻⁵ M, respectively. The reproducibility of SiO₂@APTES@FFPBA@MIPs was satisfactory and could be reused after six adsorption–desorption cycles, which indicated their high chemical stability. In addition, the recoveries of the proposed method for EP at three spiked levels of SiO₂@APTES@FFPBA@MIPs in milk and meat samples of chicken, pork and beef were 96.0–98.0%, 95.0–96.3%, 94.0–98.0% and 92.5–98.3%, respectively. The prepared SiO₂@APTES@FFPBA@MIPs enabled the recognition of low concentrations of EP in real food samples such as milk and meat. Our approach facilitates rapid, facile, selective and efficient sample preparation. Because the approach is general, we foresee rapid development and promising applications in the future.