Tryptophan-functionalized gold nanoparticles for deep UV imaging of microbial cells.
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.
University of Belgrade, Faculty of Physics, P.O. Box 368, 11001 Belgrade, Serbia.
Jelena D
JD
Pajović
University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia.
Radovan
R
Dojčilović
University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia. Electronic address: bozanic@vinca.rs.
Dušan K
DK
Božanić
University Paris-Sud 11, UMR-S785, F-94800 Villejuif, France; Inserm U785, F-94800 Villejuif, France.
Slavka
S
Kaščáková
DISCO Beamline, Synchrotron SOLEIL, F-91192 Gif sur Yvette, France.
Matthieu
M
Réfrégiers
University of Belgrade, Department of Bioengineering and Biotechnology, Faculty of Technology and Metallurgy, Karnegijeva 4, 11120 Belgrade, Serbia.
Suzana
S
Dimitrijević-Branković
University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia.
Vesna V
VV
Vodnik
University of Belgrade, Institute of Physics Belgrade, Pregrevica 118, 11080 Belgrade, Serbia.
Aleksandar R
AR
Milosavljević
ENEA Brindisi, Physical Technologies and New Materials, SS. 7, Appia, KM 706, 72100 Brindisi, Italy.
Emanuela
E
Piscopiello
Center for Advanced Materials, Qatar University, P.O. Box 2713, Doha, Qatar.
Adriaan S
AS
Luyt
University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia. Electronic address: djokovic@vinca.rs.
Vladimir
V
Djoković
D004926:Escherichia coli / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles; D046529:Microscopy, Electron, Transmission; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D014364:Tryptophan / Q000737:chemistry*
D006046:Gold; D014364:Tryptophan
E. coli; Fluorescence imaging; Functionalization; Gold nanoparticles; Tryptophan