Development of molecularly imprinted polymers for the binding of nitrofurantoin.

Novel molecularly imprinted polymers (MIPs) for the recognition of nitrofurantoin (NFT) were prepared by photoinitiated polymerisation in polar solvent using 2,6-bis(methacrylamido) pyridine (BMP) as the functional monomer and carboxyphenyl aminohydantoin (CPAH) as the analogue of the template. The binding constants of the complex between BMP and nitrofurantoin or CPAH in DMSO were determined with 1H NMR titration to be 630+/-104 and 830+/-146 M(-1), respectively. To study the influence of the functional monomer, two polymer compositions were prepared containing the template, the functional monomer and the crosslinker in the molar ratio 1:1:12 for MIP1 and 1:4:20 for MIP2, respectively. The imprinting factor at saturation concentration of nitrofurantoin, which is the ratio of the amount bound to the MIP and the non-imprinted control polymer (NIP), was determined to be 2.47 for MIP1 and 2.49 for MIP2. The cross reactivity of the imprinted polymers seems to be determined by the ability to form hydrogen bonds to the functional monomer while the shape of the molecule has no real influence.