Thin Walled Imprinted Polymer Beads Featuring Both Uniform and Accessible Binding Sites

A novel approach addressing the classical deficiencies of molecularly imprinted polymers (MIPs), that is, low binding capacity and nonuniform binding sites, is reported. The thin walled beads were produced in two steps by first grafting thin MIP films, under controlled (RAFT) or noncontrolled conditions, from porous silica beads following previously reported procedures. The resulting composites were compared in terms of film thickness, the grafted layer homogeneity, the effect of different support morphologies, and for their ability to recognize the template in chromatographic or static binding tests. Thus, using l-Phenylalanine anilide (L-PA) as template to imprint poly(MAA-co-EDMA) in such a way led to nanometer thick films where the resulting composite were able to selectively retain the template in relation to the thickness of the grafted film. In the second step, removing the silica supports from the above composites by etching, led to nanometer thin walled beads with structure, morphology and recogn...