β-Cyclodextrin decorated nanocellulose: a smart approach towards the selective fluorimetric determination of danofloxacin in milk samples

An innovative and versatile strategy of Solid Phase Microextraction (SPME) is shown by using a new type of beta-cyclodextrin-modified nanocellulose (CD-NC) as a sorbent material. beta-cyclodextrin (used as an inclusion-type selector) was covalently bonded to amine-modified nanocellulose by an amidation reaction. Such novel nanocavities were successfully applied to the selective recognition of danofloxacin (DAN), an antibiotic used to treat animal diseases, via supramolecular host-guest interactions. The SPME methodology, using a platform based on beta-cyclodextrin-decorated nanocellulose as a sorbent material, showed a wide linear fluorimetric response against DAN from 8 to 800 mu g L-1 and a detection limit of 2.5 mu g L-1. The specific recognition of DAN has been proven to be highly selective and efficient against this metabolite and other fluoroquinolones. The reusability and the high efficiency in the extraction and preconcentration of DAN in milk samples allow recoveries of 94%.