High adsorption capacity and excellent selectivity are two crucial criteria for solid-phase extraction adsorbents to be effectively applied in the separation and purification of proteins. Herein, a novel flower-like microsphere structure grafted with poly(ethylene glycol) diamine (NH2–PEG–NH2) were proposed for the high selective isolation and superior adsorption capacity of bovine hemoglobin. This flower-like microsphere adsorbent, abbreviated as ZnO@PDA@PEG, was formed via self-polymerization of dopamine on the ZnO microspheres surface and substantially modified with poly(ethylene glycol) diamine through the Michael reaction, which provides numerous binding sites for promoting a superior adsorption capacity of 50,745.9 mg g–1 toward bovine hemoglobin. Moreover, this adsorbent exhibited favorable adsorption selectivity toward bovine hemoglobin by reducing the nonspecific adsorption by virtue of the unique steric hindrance effect of poly(ethylene glycol) diamine. The adsorbed bovine hemoglobin was easily collected by using 0.5% sodium dodecyl sulfate with a recovery rate of 87.9%. Circular dichroism spectra indicated no conformational change for bovine hemoglobin during the adsorption–elution process. Finally, ZnO@PDA@PEG demonstrated outstanding separation performance toward bovine hemoglobin from the complex bovine whole blood sample, successfully addressing the critical challenge of nonspecific adsorption during the selective isolation of target proteins from real-world biological matrices.
Wang et al. (Fri,) studied this question.