Ni(II)-decorated porous titania microspheres as a stationary phase for column chromatography applications: Highly selective purification of hemoglobin from human blood.

Abstract

Titania (TiO2)-based monodisperse-porous stationary phase/sorbent was synthesized by decoration of Ni(II) ions onto TiO2 microspheres 4.2\u202fµm in size, obtained by a staged-shape template hydrolysis and condensation protocol. Ni(II) ions were attached onto iminodiacetic acid-3-glycidoxypropyltrimethoxysilane (IDA-GPTMS) bound-titania microspheres by metal-chelate complex formation. The appropriate mean size, sufficiently high surface area and high porosity providing an appropriate column permeability make Ni(II)-decorated TiO2 microspheres a good sorbent/stationary phase for batch/continuous-column chromatography applications. Ni(II)-decorated TiO2 microspheres were investigated as a sorbent for purification of a typical histidine-rich protein, hemoglobin (Hb) via immobilized metal affinity chromatography (IMAC) in batch fashion, by including bovine serum albumin (BSA) as reference. The saturation capacities of batch adsorption runs performed with bovine Hb and BSA were determined as 137\u202f±\u202f9 and 45\u202f±\u202f3\u202fmg/g, respectively. Human Hb with the purity of >\u202f95% was recovered from whole blood by IMAC conducted in batch-fashion. Ni(II)-decorated microspheres were also evaluated as a stationary phase in a microfluidic-IMAC system, in which, human Hb was recovered from whole blood with a purity of 85%. The microfluidic-IMAC system constructed here, based on monodisperse-porous TiO2 microspheres, is a promising tool for genomics/proteomics applications involving isolation of valuable biomolecules from low-volume samples.