Deep UV fluorescence imaging study of Candida albicans cells treated with gold-riboflavin hydrocolloids Jelena D. Pajovic ´ 1 • Radovan Dojc ˇilovic ´ 2 • Dus ˇan K. Boz ˇanic ´ 2 • Vesna V. Vodnik 2 • Suzana Dimitrijevic ´-Brankovic ´ 3 • Slavka Kas ˇc ˇakova ´ 4,5 • Matthieu Re ´fre ´giers 6 • Milica Markelic ´ 7 • Vladimir Djokovic ´ 2 Received: 6 November 2015 / Accepted: 21 April 2016 Ó Springer Science+Business Media New York 2016 Abstract Fluorescent nanostructures were prepared by functionalization of gold nanoparticles with riboflavin molecules and used as probes for synchrotron radiation deep ultraviolet (SR-DUV) fluorescence imaging of gluteraldehyde-fixed Candida albicans cells. The nanoparticles were characterized by transmission electron microscopy (TEM) and optical spectroscopy techniques. The TEM analysis showed that the nanostructures were 6 nm in diameter, while the results of the fluorescence spectroscopies confirmed the photoluminescence of the nanoparticles. The SR-DUV imaging showed that it was possible to distinguish the fluorescence of the nanoparticles from the autofluorescence of the cells, as well as that the local maxima of the signal pertaining to the fluorescence of gold- riboflavin nanostructures were mostly positioned on the surfaces of the C. albicans cells of spherical morphology. This article is part of the Topical Collection on Advances in the Science of Light. Guest Edited by Jelena Radovanovic, Milutin Stepic, Mikhail Sumetsky, Mauro Pereira and Dragan Indjin. & Dus ˇan K. Boz ˇanic ´ bozanic@vinca.rs & Vladimir Djokovic ´ djokovic@vinca.rs 1 Faculty of Physics, University of Belgrade, P. O. Box 368, Belgrade 11001, Serbia 2 Vinc ˇa Institute of Nuclear Sciences, University of Belgrade, P. O. Box 522, Belgrade 11001, Serbia 3 Department of Bioengineering and Biotechnology, Faculty of Technology and Metallurgy, University of Belgrade, Karnegija 4, Belgrade 11120, Serbia 4 Inserm U785, 94800 Villejuif, France 5 Univ. Paris-Sud 11, UMR-S785, 94800 Villejuif, France 6 DISCO beamline, Synchrotron SOLEIL, 91192 Gif sur Yvette, France 7 Faculty of Biology, University of Belgrade, Studentski trg 16, Belgrade 11000, Serbia 123 Opt Quant Electron (2016)48:311 DOI 10.1007/s11082-016-0578-y