Preparation of bentonite-cysteine (Bent-Cys) Micro-composite affinity sorbents for ferritin adsorption

Abstract

his study focused on developing bentonite-cysteine micro-composite «affinity sorbents (Bent-Cys) (38-105 |am) for Ferritin adsorption from aqueous solutions. The pseudo-specific affinity ligand L-cysteine was immobilized by covalent binding onto the bentonite structure. X-ray diffraction and FTIR analysis of Bent-Cys composite affinity sorbents were performed. The specific surface area of the bentonite and Bent-Cys micro-composite structures were found to be 33.0 and^2.8 m2/g, respectively. Elemental analysis of immobilized L-cysteine for nitrogen was estimated to be 541.3 |j.mol/g bentonite. The non-specific ferritin adsorption onto bentonite structure was negligible (ca. 0.9 mg/g). Higher adsorption values up to 40.0 mg/g were obtained in which Bent-Cys micro-composite affinity sorbents were used from aqueous solutions. Adsorption studies were performed to evaluate the effect of initial concentration of ferritin, pH, temperature. The desorption characteristics of Bent-Cys micro-composite affinity sorbents were also studied. The maximum amount of ferritin adsorption from aqueous solution was observed at pH 4.0. Ferritin molecules could be repeatedly adsorbed and desorbed with the micro-composite affinity sorbent system without noticeable loss in the ferritin adsorption capacity.