Molecularly imprinted polymers for corticosteroids: analysis of binding selectivity

In this work we prepared a library of cortisol-imprinted polymers via a sequential approach by combining 10 different functional monomers , 7 cross-linkers and 5 porogen solvents . The best combinations of functional monomers, cross-linkers and porogen solvents in terms of cortisol binding were used to prepare three imprinted polymers ― polyacrylamide-co-ethylene dimethacrylate (porogen: chloroform), poly-4-vinylpyridineco- ethylene dimethacrylate (porogen: chloroform) and polyacrylamide-co-ethylene dimethacrylate (porogen: acetonitrile) ― whose selectivity towards 10 synthetic corticosteroids and 4 natural steroidal hormones was tested. The experimental results obtained show how different combinations of functional monomers, cross-linkers and porogen solvents produce cortisol-imprinted polymers with very different selectivity patterns, and that a careful optimization of the pre-polymerization mixtures makes it possible to increase the number of target steroids recognized by the resulting imprinted polymer. Moreover, through the use of a Free-Wilson analysis of the binding selectivity, it has been possible to obtain insights on the steroidal structural motifs able to increase or decrease the molecular recognition of corticosteroids by the imprinted polymers