An innovative approach to molecularly imprinted capillaries for polar templates by grafting polymerization.
Molecularly imprinted polymers have been successfully used as selective stationary phases in capillary electrophoresis. Notwithstanding, this technique suffers from several drawbacks as the loss of molecular recognition properties in aqueous media and the lack of feasibility for imprinted systems directed towards highly polar templates soluble in aqueous environments only. Thus, the preparation of imprinted polymers for highly polar, water-soluble analytes, represents a challenge. In this work, we present an innovative approach to overcome these drawbacks. It is based on a surface molecular imprinting technique that uses preformed macromonomers as both functional recognition elements and cross-linking agents. A poly-2-hydroxyethyl-co-methacrylic acid linear polymer was grafted from the surface of silica capillaries. The grafted polymer was exhaustively esterified with methacrylic anhydride to obtain polyethylendimethacrylate-co-methacrylic acid linear chains. Then, as a proof of concept, an adequate amount of a very polar template like penicillin V was added in a hydro-organic mixture, and a thin layer of imprinted polymer was obtained by cross-linking the polymer linear chains. The binding behaviour of the imprinted and non-imprinted capillaries was evaluated in different separation conditions in order to assess the presence of template selectivity and molecular recognition effects. The experimental results clearly show that this innovative kind of imprinted material can be easily obtained in very polar polymerization environments and that it is characterized by enhanced molecular recognition properties in aqueous buffers and good selectivity towards the template and strictly related molecules.
Laboratory of Bioanalytical Chemistry, Department of Chemistry, University of Torino, 10125 Torino, Italy.
Cristina
C
Giovannoli
Cinzia
C
Passini
Patrizia
P
Baravalle
Laura
L
Anfossi
Gianfranco
G
Giraudi
Claudio
C
Baggiani
D019817:Benzoic Acid / Q000032:analysis / Q000302:isolation & purification; D019075:Electrophoresis, Capillary; D057927:Hydrophobic and Hydrophilic Interactions; D000432:Methanol / Q000737:chemistry; D008768:Methylmethacrylates / Q000138:chemical synthesis / Q000737:chemistry; D054802:Molecular Imprinting / Q000379:methods*; D010404:Penicillin V / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D010406:Penicillins / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D011095:Polyethylenes / Q000138:chemical synthesis / Q000737:chemistry; D011102:Polyhydroxyethyl Methacrylate / Q000138:chemical synthesis / Q000737:chemistry; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000138:chemical synthesis / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties
D008768:Methylmethacrylates; D010406:Penicillins; D011095:Polyethylenes; D011109:Polymethacrylic Acids; D012997:Solvents; D011102:Polyhydroxyethyl Methacrylate; C040206:HTR composite; D012822:Silicon Dioxide; D019817:Benzoic Acid; D000432:Methanol; D010404:Penicillin V