Direct preparation of porous cellulose microspheres via a self-growth process on bamboo fibers and their functionalization for specific adsorption of histidine-rich proteins

The traditional preparation of cellulose microspheres always involves tedious synthetic procedures (e.g., dissolution, emulsification and regeneration) and inevitable organic solvents, which undergoes both high production cost and environmental contamination. To overcome these issues, a feasible and green synthesis strategy is proposed to construct porous cellulose microspheres (PCMs) via one-step spontaneous formation relying on sodium periodate oxidation of pure bamboo fibers. By this strategy, a cluster of robust cellulose microspheres grow up on the surface of bamboo fibers in aqueous phase through amorphous oxidized cellulose self-assembly accumulation and then drop out when their sizes increase to about 15 µm. After being immobilized with Cu(II), the prepared cellulose microspheres serve as metal affinity adsorbent for proteins adsorption, showing high adsorption capacity, good selectivity and excellent reusability for bovine hemoglobin (BHb). Together with green and easy synthesis, the novel cellulose microspheres show a promising alternative to commercially available adsorbent support.