Cell Imaging with Fluorescent Bi-Metallic Nanoparticles

Abstract

Last decades various imaging techniques have been applied in biological and biomedical research, such as magnetic resonance imaging, different types of tomography, fluorescence/bioluminescence, ultrasound, as well as multimodality approaches. Fluorescence imaging, especially in combination with nanoscale materials, is a very prospective tool for experiments in vivo and clinical applications due to its high temporal and spatial resolutions. Fluorescent n anoparticles (NPs), having ability to interact with biomolecules both on the surface of and inside the cells, may revolutionize the cell imaging approaches for diagnostics and therapy. In our investigation we report about new method of cell imaging with fluorescent bi-metallic NPs synthesized by chemical reduction of the relevant ions. As the model of living organism, the cells of yeast Hansenula polymorpha were used. All NPs in minimal concentration (up to 0.05 mM) was proved to be nontoxic for yeast cells. The NPs and NPs -modified cells were characterized with the methods of UV-VIS spectroscopy, scanning electron microscopy, atom force microscopy, transmission electron m icroscopy and fluorescence microscopy. The bimetallic NPs, possessing the stable fluorescence in solution and inside the cells, allow to observe the phenomenon of NPs transferring from parental to daughter cells through at least three generations followed by releasing from the modified cells. The fluorescent NPs synthesized being small, non-toxic and fluorescent was shown to be perspective tool for cell imaging. KeywordsNanoparticles of noble metals· Fluorescence ·Toxicity of nanoparticles · Yeast Hansenula polymorpha ·Cell imaging .

Metallic Nanoparticles Obtained via “Green” Synthesis as a Platform for Biosensor Construction

“…For example, the spectrum of gPdNPs has a peak at 390 nm (Figure 1), which is specific for PdNPs [18,61]. A peak of gAuNPs in the range 525-590 nm is specific for chemically-synthesized AuNPs of different sizes, according to data reported in the literature [8,12,13,19,38,42,43,48] as well as our results [56,62]. The color, size and shape of AuNPs and gAuNPs are dependent on the NPs' synthesis conditions: culture liquid of a 1-day culture incubated for 3 days with HAuCl 4 produces a dark blue solution of small gAuNPs with a peak at 525 nm.…”