title: Influence of salt ions on binding to molecularly imprinted polymers.
abstract: Salt ions were found to have an influence on template binding to two model molecularly imprinted polymers (MIPs), targeted to penicillin G and propranolol, respectively, in water-acetonitrile mixtures. Water was detrimental to rebinding of penicillin G whereas propranolol bound in the entire water-acetonitrile range tested. In 100% aqueous solution, 3-M salt solutions augmented the binding of both templates. The effects followed the Hofmeister series with kosmotropic ions promoting the largest increase. Binding was mainly of a non-specific nature under these conditions. In acetonitrile containing low amounts of water, the specific binding to the MIPs increased with the addition of salts. Binding of penicillin G followed the Hofmeister series while an ion-exchange mechanism was observed for propranolol. The results suggest that hydration of kosmotropic ions reduces the water activity in water-poor media providing a stabilizing effect on water-sensitive MIP-template interactions. The effects were utilized to develop a procedure for molecularly imprinted solid-phase extraction (MISPE) of penicillin G from milk with a recovery of 87%.
authors.affiliation: Biomedical Polymer Technology, Department of Experimental Medical Science, Biomedical Center, D11, Lund University, 221 84 Lund, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Kempe
authors.forename: Maria
authors.initials: M
authors.lastname: Kempe
mesh_terms: D007477:Ions / Q000737:chemistry; D054802:Molecular Imprinting; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry; D010400:Penicillin G / Q000737:chemistry*; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011433:Propranolol / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*; D005466:Fluorocarbons
chemical_list: D007477:Ions; D009570:Nitriles; D010400:Penicillin G; D010649:Phenylalanine; D011108:Polymers; D011433:Propranolol; D012965:Sodium Chloride; C097647:4-tert-butoxycarbonylamino-3-hydroxy-2-(2,3,4,5,6-pentafluorophenyl)-5-phenyl-2-pentenenitrile; D005466:Fluorocarbons