Tryptophan-functionalized gold nanoparticles for deep UV imaging of microbial cells

Jelena D Pajović; Radovan Dojčilović; Dušan K Božanić; Slavka Kaščáková; Matthieu Réfrégiers; Suzana Dimitrijević-Branković; Vesna V Vodnik; Aleksandar R Milosavljević; Emanuela Piscopiello; Adriaan S Luyt; Vladimir Djoković

doi:10.1016/j.colsurfb.2015.08.050

Tryptophan-functionalized gold nanoparticles for deep UV imaging of microbial cells

Colloids Surf B Biointerfaces. 2015 Nov 1:135:742-750. doi: 10.1016/j.colsurfb.2015.08.050. Epub 2015 Aug 28.

Affiliations

¹ University of Belgrade, Faculty of Physics, P.O. Box 368, 11001 Belgrade, Serbia.
² University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia.
³ University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia. Electronic address: bozanic@vinca.rs.
⁴ University Paris-Sud 11, UMR-S785, F-94800 Villejuif, France; Inserm U785, F-94800 Villejuif, France.
⁵ DISCO Beamline, Synchrotron SOLEIL, F-91192 Gif sur Yvette, France.
⁶ University of Belgrade, Department of Bioengineering and Biotechnology, Faculty of Technology and Metallurgy, Karnegijeva 4, 11120 Belgrade, Serbia.
⁷ University of Belgrade, Institute of Physics Belgrade, Pregrevica 118, 11080 Belgrade, Serbia.
⁸ ENEA Brindisi, Physical Technologies and New Materials, SS. 7, Appia, KM 706, 72100 Brindisi, Italy.
⁹ Center for Advanced Materials, Qatar University, P.O. Box 2713, Doha, Qatar.
¹⁰ University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia. Electronic address: djokovic@vinca.rs.

PMID: 26340364
DOI: 10.1016/j.colsurfb.2015.08.050

Abstract

Biocompatible fluorescent nanostructures were prepared by a functionalization of gold nanoparticles with the amino acid tryptophan. The gold-tryptophan bioconjugates were investigated by TEM and HRTEM and various spectroscopy methods (XPS, FTIR, UV-vis and photoluminescence). It was found that the gold nanoparticles, initially 8 nm in diameter, aggregate in the presence of the amino acid. From the XPS and FTIR spectroscopy results, it was concluded that the tryptophan gold interactions mainly take place via indole and carboxyl groups. Although the indole group is involved in the interaction with the gold surfaces, the tryptophan-gold hybrids showed strong fluorescence due to the presence of multilayers of tryptophan. Deep ultra violet (DUV) imaging performed at the SOLEIL synchrotron showed that it is possible to detect these hybrid nanostructures within Escherichia coli cells.

Keywords: E. coli; Fluorescence imaging; Functionalization; Gold nanoparticles; Tryptophan.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Escherichia coli / chemistry*
Gold / chemistry*
Metal Nanoparticles*
Microscopy, Electron, Transmission
Spectrophotometry, Ultraviolet / methods*
Tryptophan / chemistry*

Substances

Gold
Tryptophan