Aptamer-functionalized mesoporous metal-organic framework with ultrahigh adsorption capacity for selective isolation...

Mesoporous Zr-based MOF material MPAUiO was prepared by nanoemulsion-guided assembly technology using polyether compound as soft template, then modified with lactoferrin aptamer (LFA) via Schiff-base reaction to give aptamer-functionalized mesoporous composite LFA@MPAUiO. The multiple hydrogen-bonding interactions between the aptamer bases and the amino acid residues of protein endowed LFA@MPAUiO composite with good adsorption selectivity for lactoferrin. Thermodynamic investigations indicated that the adsorption behavior of LFA@MPAUiO for lactoferrin conformed to the Langmuir isothermal model, giving an ultrahigh adsorption capacity up to 1308 mg g^-1 under pH = 5. The adsorbed protein could be effectively recovered by 1.0% NH₃·H₂O (v/v) with a recovery of 92.8%. SDS-PAGE analysis demonstrated that high-purity lactoferrin was isolated from bovine whey with LFA@MPAUiO composite. In vitro antioxidant assays revealed that the isolated lactoferrin owned high antioxidant activity. The research well indicated that LFA@MPAUiO based protein isolation process holds great promise for practical applications.