Size selective protein adsorption on thiol-functionalised SBA-15 mesoporous molecular sieve
The mesoporous silica SBA-15, functionalised with propylthiol groups during synthesis and rendered porous (mean pore diameter 51 Å) by extraction of surfactant template molecules, shows strong and size selective adsorption of proteins, selectively excluding those with molecular weights of ca. 40000 u and above. A model for the adsorption process is proposed, in which reversible physisorption is followed by irreversible chemisorption. Adsorption of proteins on an unfunctionalised SBA-15 from which the template has been removed by calcination, (mean pore diameter 56 Å) shows shape selective and reversible adsorption of proteins with molecular weights of ca. 43000 u and below.