[Zurück]

I. Ten-Doménech, B. Lendl, G. Quintas, M. Vento, J. Kuligowski:
"Glutathione detection in blood: a trial of strength between Mass Spectrometry (MS) and Surface Enhanced Raman Scattering (SERS)";
Poster: SciX Conference 2020, Online; 12.10.2020 - 15.10.2020.

Glutathione (GSH) is the most abundant non-enzymatic antioxidant in most cells and tissues, including whole blood, and its usefulness as a biomarker for oxidative stress monitoring has been known for decades. However, its accurate quantification remains challenging due to the limited stability of GSH in biofluids. Here the strengths and weaknesses of two complementary approaches for the quantification of GSH in whole blood samples are compared: 1) ultraperformance liquid chromatography coupled to tandem MS (UPLC-MS/MS) from dried blood spot (DBS) samples after in-situ derivatization employing N-ethylmaleimide (NEM) and 2) the direct determination based on SERS employing a portable Raman probe. Our results show that DBS cards impregnated with NEM solution allow the simultaneous quantification of reduced and oxidized GSH. NEM-DBS cards are stable during at least one week and 10 μL blood samples can be stored after in-situ derivatization during at least 24h at 4 ⁰C with no significant changes in the GSH and GSSG concentrations. On the other hand, the use of an internal standard (GSH-13C15N) allows the accurate quantification of GSH in 5 μL whole blood samples by SERS within minutes with minimal sample manipulation, by using a paper-based device with deposited silver nanoparticles suitable for point-of-care testing. Both methods will be tested for GSH monitoring in newborns and their performance will be compared in the near future.