Nano-gold in time-of-flight mass spectrometry of biological samples


L. Kolářová^1, L. Kučera^2, L. Prokeš^1, P. Vaňhara^2,3, A. Hampl^2,3, J. Havel^1,3

^1Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5/A14, 625 00 Brno,
Czech Republic

^2Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech
Republic

^3International Clinical Research Center, St. Anne´s University Hospital, Brno, Czech Republic,
Pekařská 53, 656 91 Brno, Czech Republic


The use of gold nano-particles (Au-NP) in science and technology is permanently increasing. Due to
their unique physico-chemical properties, Au-NP are highly suitable for mass spectrometry (MS) of
complex bio-molecules or intact cells and tissues as both calibrants and matrices. Au-NP are
generally produced mostly by reduction of Au (III) with a redox agent. In the current work we
demonstrate and discuss our recent results on use of Au-NP in MS of cells and tissues. 1)
Internal/external calibration in MS: precise calibration in MS is an essential prerequisite of
standard measurements. The use of Au clusters generated from various Au-NP provides a reliable tool
for calibration in time-of-flight MS. The Au is monoisotopic, thus the determination of accurate
mass is straightforward and fast compared to common calibration standards like peptides/proteins
etc. 2) Use of Au-NP as matrix: the Au-NP (e.g. in the form of flower-like Au-NP) enhance the
ionization of complex biomolecules. This enhancement is presumably due to SALDI (Surface Assisted
Laser Desorption Ionization) or NALDI (Nano-particles Assisted LDI) effects. Even the combination
of classical MALDI matrix with Au-NP offers significant advantages as it was recently reported [1].
3) Au-NP in MS analysis of intact cells: gold is highly biocompatible; Au-NP can be easily absorbed
by endocytosis to cell cytoplasm and increase the signal intensity of peptides and proteins during
MS analysis. 4) Tissue imaging: similarly to Au-NP-mediated intact-cell MS, treatment of tissue
sections with Au-NP-enriched matrices positively affects the overall quality of mass spectra and
improves the tissue MS analysis. Concluding, the use of Au-NP brings new and exciting possibilities
in MS of biomolecules.


References: [1] L. Kolářová, L. Kučera, P. Vaňhara, A. Hampl, J. Havel, RCMS 29 (2015) 1585-1595.