title: Optical sensors with molecularly imprinted nanospheres: a promising approach for robust and label-free detection of small molecules.
abstract: Molecularly imprinted nanospheres obtained by miniemulsion polymerization have been applied as the sensitive layer for label-free direct optical sensing of small molecules. Using these particles as the sensitive layer allowed for improving response times in comparison to sensors using MIP layers. As a model compound, well-characterized nanospheres imprinted against L-Boc-phenylalanine anilide (L-BFA) were chosen. For immobilization, a simple concept based on electrostatic adsorption was used, showing its applicability to different types of surfaces, leading to a good surface coverage. The sensor showed short response times, good selectivity, and high reversibility with a limit of detection down to 60 μM and a limit of quantitation of 94 μM. Furthermore, reproducibility, selectivity, and long-term stability of the sensitive layers were tested. The best results were achieved with an adsorption on aminopropylsilane layers, showing a chip-to-chip reproducibility of 22%. Furthermore, the sensors showed no loss in signal after a storage time of 1 year.
authors.affiliation: Institute of Physical and Theoretical Chemistry, Tübingen University, Auf der Morgenstelle 18, 72072 Tübingen, Germany. felix.kolarov@uni-tuebingen.de
authors.forename: Felix
authors.initials: F
authors.lastname: Kolarov
authors.forename: Klaus
authors.initials: K
authors.lastname: Niedergall
authors.forename: Monika
authors.initials: M
authors.lastname: Bach
authors.forename: Günter E M
authors.initials: GE
authors.lastname: Tovar
authors.forename: Günter
authors.initials: G
authors.lastname: Gauglitz
mesh_terms: D000596:Amino Acids / Q000032:analysis; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D054802:Molecular Imprinting; D054118:Nanospheres / Q000737:chemistry*; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000032:analysis; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D011108:Polymers; C060198:phenylalanine anilide; D010649:Phenylalanine