▎ 摘　　要

A novel magnetic sorbent, one-dimensional (1D) magnetite hydroxyapatite nanorods on two-dimensional (2D) reduced graphene oxide (MHAp/RGO) was developed for selective separation of hemoglobin (Hb). The MHAp/ RGO nanocomposite was prepared through a hydrothermal method at 180 degrees C for 12 h. Nucleation growth mechanism was analyzed for the formation of the nanocomposite. Electron microscopy analysis showed that the 1D MHAp with average diameter and length of 25 and 200 nm respectively were uniformly grown on 2D RGO sheets. Ternary phases of magnetite, HAp, and RGO in the samples were studied using various physicochemical characterization tools. The obtained MHAp/RGO nanocomposite was used as a high-performance magnetic sorbent for selective adsorption and controlled release of Hb. The as-prepared MHAp/RGO nanocomposite exhibited a maximum adsorption capacity of 1012 mg g(-1) at near the isoelectric point (pI((Hb))) of Hb (pH 7.0). Hb adsorption behavior on the nanosorbent was analyzed through the adsorption mechanism, equilibrium isotherms, and kinetic models. Also, the adsorbed Hb on the nanosorbent could be effectively recovered up to 86% at pH 4.0 within 45 min. The present study revealed that the developed magnetic sorbent shows a potential scope for pH-dependent Hb protein isolation and release, thus making it suitable for biomedical applications.