Efficient synthesis of hollow solid phase extraction adsorbent using L-lysine modified polydopamine as coating shell for the selective recognition of bilirubin

Abstract

Hollow structured l-lysine modified polydopamine coating shells (h-PDA@L-lys) were prepared using polystyrene (PS) as sacrificial support, the dopamine was used to coat PS by self-polymerization, L-lys as adsorpt ligand. The PS can be etched to form hollow structure, where more binding sites locate on the inner and outer surfaces can be utilized maximum. The h-PDA@L-lys were used as adsorbent for the specific bilirubin (BR) enrichment from animal livers. The adsorbent was characterized in details and its selectivity and binding capacity were evaluated. The experimental conditions (sample pH, adsorbent amounts, eluent types, eluent pH and volume) were optimized. The results indicate that h-PDA@L-lys exhibite good selective adsorption ability and higher adsorption amount. According to the adsorption experiments, the adsorption kinetics obey pseudo-second-order adsorption kinetics and the equilibrium data are best described by Langmuir isotherm model. The saturated adsorption capacity is 12.0 mg g−1, which is not only higher than the adsorption capacities of non-hollow adsorbents, but also superior to those of many reported adsorbents for enrich of BR. Moreover, this method was successfully applied in the selective recognition of BR in animal livers. Thus, this work provide potential possibility and practical platform for detection of BR in complex matrices.