No abstract

We developed a novel metal adsorbent composed of bio-based materials, cellulose and a protein. The approach involved the immobilization of hexa-histidine tag (His6), which shows an affinity for intermediate acid (metal ion) in Hard and Soft Acids and Bases (HSAB) theory, on cellulose by fusing with carbohydrate-binding module (CBM). The results show that CBM-His6-bound cellulose has adsorption selectivity reflecting the original properties of His6. Additionally, we prepared three configurations of CBM-His6 proteins, which were subsequently immobilized on a filter paper for Ni 2+ ion adsorption. Of these configurations, we found the protein containing two His6 tags at each terminus (N-and C-) of CBM exhibited the highest metal adsorption ability. Furthermore, XPS analysis confirmed the binding of Ni 2+ ions on the cellulose.