Analytica Chimica Acta 784 (2013) 65–71 Contents lists available at SciVerse ScienceDirect Analytica Chimica Acta j ourna l ho mepage: www.elsevier.com/locate/aca Determination of fluoroquinolone antibiotics through the fluorescent response of Eu(III) based nanoparticles fabricated by layer-by-layer technique Nikolay Davydov a , Rustem Zairov a , Asiya Mustafina a,∗ , Viktor Syakayev a , Dmitry Tatarinov a , Vladimir Mironov a , Sergei Eremin b , Alexander Konovalov a , Marat Mustafin c a A.E. Arbuzov Institute of Organic and Physical Chemistry, Arbuzov Street, 8, Kazan, Russia b Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow 119991, Russia c Kazan (Volga Region) Federal University, Kremlevskaya Street, 18, Kazan 420008, Russia h i g h l i g h t s • Novel route of fluorescent deter- mination of fluoroquinolones was developed. • Fluorescent response arises from ligand exchange in Eu(III) based col- loids. • Fluorescent response is affected by concentration and structure of fluo- roquinolones. • Conditions of discrimination between fluoroquinolones are revealed. g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 29 November 2012 Received in revised form 26 April 2013 Accepted 29 April 2013 Available online 9 May 2013 Keywords: Fluoroquinolones Luminescence Europium(III) Nanoparticles Capsules Layer-by-layer a b s t r a c t The present work introduces the determination of fluoroquinolone antibiotics (FQs) in aqueous solutions through the fluorescent response of Eu(TTA) 3 and [Eu(TTA) 3 1] (TTA - and 1 are thenoyltrifluoroacetonate and phosphine oxide derivative) complexes encapsulated into the polyelectrolyte capsules fabricated through layer-by-layer deposition of poly(sodium 4-styrenesulfonate) (PSS) and polyethyleneimine (PEI). The variation of luminescent core, polyelectrolyte deposition and concentration conditions reveals two modes of fluorescent response on FQs of diverse structure namely the sensitization and quenching of Eu(III) centered luminescence. The obtained regularities reveal the ternary complex formation and the ligand exchange occurring at the interface of polyelectrolyte coated [Eu(TTA) 3 1] based colloids as the reasons of the diverse fluorescent response of Eu(III) centered luminescence on FQs. The factors affecting the fluorescent response have been revealed, which are: the content of luminescent core, the mode of polyelectrolyte deposition, concentration and structure of FQs. The discrimination of moxifloxacin and lomefloxacin from levofloxacin, ofloxacin, difloxacin, perfloxacin through the quenching of Eu(III) luminescence in PSS-[Eu(TTA) 3 1] colloids has been revealed. © 2013 Elsevier B.V. All rights reserved. ∗ Corresponding author. Tel.: +7 8432732253; fax: +7 8432732253. E-mail addresses: asiyamust@mail.ru, asiya@iopc.ru (A. Mustafina). 1. Introduction The luminescent lanthanide complexes are a top of current interest during recent decades due to their technological, analyti- cal and medical application [1–8]. The applicability of lanthanide complexes in biosensing is well documented in literature [5–10]. 0003-2670/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.aca.2013.04.054