title: Naproxen-imprinted xerogels in the micro- and nanospherical formsby emulsion technique.
abstract: Naproxen-imprinted xerogels in the microspherical and nanospherical forms were prepared by W/O emulsion and microemulsion, respectively. The work evolved from a sol–gel mixture previously reported for bulk synthesis. It was relatively simple to convert the original sol–gel mixture to one amenable to emulsion technique. The microspheres thus produced presented mean diameter of 3.7 μm, surface area ranging 220–340 m2/g, selectivity factor 4.3 (against ibuprofen) and imprinting factor 61. A superior capacity (9.4 μmol/g) was found, when comparing with imprints obtained from similar pre-gelification mixtures. However, slow mass transfer kinetics was deduced from column efficiency results. Concerning the nanospherical format, which constituted the first example of the production of molecularly imprinted xerogels in that format by microemulsion technique, adapting the sol–gel mixture was troublesome. In the end, nanoparticles with diameter in the order of 10 nm were finally obtained, exhibiting good indications of an efficient molecular imprinting process. Future refinements are necessary to solve serious aggregation issues, before moving to more accurate characterization of the binding characteristics or to real applications of the nanospheres.
authors.affiliation: Centro de Investigação em Química - CIQUP, Faculty of Science, University of Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal.
authors.forename: Mariana
authors.initials: M
authors.lastname: Ornelas
authors.affiliation: Centro de Investigação em Química - CIQUP, Faculty of Science, University of Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal. Electronic address: mazenha@fc.up.pt.
authors.forename: Manuel
authors.initials: M
authors.lastname: Azenha
authors.affiliation: Centro de Investigação em Química - CIQUP, Faculty of Science, University of Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Pereira
authors.affiliation: Centro de Investigação em Química - CIQUP, Faculty of Science, University of Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal.
authors.forename: A Fernando
authors.initials: AF
authors.lastname: Silva
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D004655:Emulsions; D005782:Gels / Q000737:chemistry; D007700:Kinetics; D008863:Microspheres; D054118:Nanospheres; D009288:Naproxen / Q000737:chemistry*
chemical_list: D004655:Emulsions; D005782:Gels; D009288:Naproxen