Copper ion based metal–organic framework nanomaterials with roughness enhanced protein adhesion for high-efficiency hemoglobin separation

Abstract

The development of well-designed adsorption materials for the effective and specific purification of hemoglobin (Hb) from complex samples for disease diagnosis is still highly required. Herein, inspired by the concept of roughness enhanced protein adhesion, a surface rough copper ion based metal–organic framework metal affinity nanomaterial composed of Cu²⁺ and 2-methylimidazole (denoted as Cu-MOF) was prepared by a simple method and used for Hb enrichment. Due to the high density of Cu²⁺ and rough surface of Cu-MOF, Cu-MOF exhibits higher adsorption capacity for bovine hemoglobin (BHb) than the other histidine (His)-rich proteins, which contain fewer surface-exposed His residues. The maximum binding capacity Cu-MOF to BHb was up to 4161.7 mg g⁻¹. Moreover, Cu-MOF has the characteristics of a fast adsorption rate (within 60 min), well-selectivity, and excellent recyclability (in 5 cycles). In addition, Cu-MOF was able to bind specifically with BHb in bovine blood samples. Therefore, this surface rough Cu-MOF can be used as a potential adsorbent for high-efficiency separation of Hb, which indicates its potential application in further analysis of complex biological samples.