Chitosan/carbon nanotube composites for the isolation of hemoglobin in the presence of abundant proteins

A cross-linked chitosan/multi-wall carbon nanotube (MWCNTs) nanocomposite is prepared via surface deposition-cross linking. The nanocomposite is characterized by means of FT-IR, SEM and TGA analysis, indicating that a chitosan layer is well coated on the surfaces of the MWCNTs, weighing about 35% of the total mass. Investigations on the performance of the chitosan/MWCNTs nanocomposite to the adsorption or loading of hemoglobin indicated that the adsorption equilibrium time is reduced from a few hours in the conventional protocols to 25 min in the present case. A theoretical adsorption capacity of 15.41 mu g mg(-1) is achieved, corresponding to a 6-fold improvement when compared to that obtained by using conventional chitosan particles in the micrometre range at a same mass condition. The nanocomposite is used as an adsorbent for the isolation of hemoglobin from human whole blood, the SDS-PAGE results indicated that successful separation of hemoglobin is obtained in the presence of large amount of abundant protein, e.g., human serum albumin.