Bisphenol A analog-imprinted polymers prepared by an immobilized template on a modified silica microsphere matrix

Bisphenol A (BPA)-recognizing imprinted polymers were synthesized using a template immobilized on silica where the template was grafted to aminopropyl silica. The silica-template conjugate was co-polymerized with a cross-linker (ethylene glycol dimethacrylate) and a functional monomer (4-vinylpyridine or methacrylic acid). The synthesized silica-polymer composites were treated with an aqueous NH4HF2 solution to dissolve the silica matrix. The 4-vinylpyridine-based imprinted polymer showed strong binding affinity to BPA and structurally related compounds having two hydroxyl groups at the 4,4'-position in the bisphenol structure.