Functionalization and Characterization of Immobilized Metal Affinity Hydrogel Membranes

Abstract

Previous studies have shown that functionalization
of hydrogel membranes with metal affinity ligands increases the
separation potential of the membranes for purification of
biological systems. To achieve separation, histidines that are
exposed on the proteins surface are attracted and attach to the
metal ion within the IMA membrane matrix. The effectiveness of
these membranes depends on several factors including, but not
limited to, type of chelating group, the metal ion, and solution
buffer. This paper is concerned with crosslinking of poly (vinyl)
alcohol (PVA) with varied degrees of crosslinking that was
subsequently functionalized with the immobilized metal affinity
(IMA) group, that included a spacing element, (1, 4 Butanediol
Diglycidyl ether (1,4 BDE)), chelator (NTA (Nitrilotriacetic
acid)), and metal (Nickel (Ni2+). The impact of chelating ligand
and glutaraldehyde concentration on the swelling and bound
metal content was determined. Additionally, Fourier-transform
infrared spectroscopy (FTIR) was used to examine the functional
groups for the control (without metal attached) and affinity (with
metal attached) membranes. Ultimately, this study suggests that
crosslinking membranes with a higher glutaraldehyde percentage
yielded a higher content of bound nickel.