MoS2/TiO2/SiNW surface as an effective substrate for LDI-MS detection of glucose and glutathione in real samples

Abstract

Here, we report for the first time, the use of molybdenum disulfide/titanium oxide/silicon nanowires (MoS₂/TiO₂/SiNW) surfaces for SALDI-MS detection as alternative to MALDI-MS method. Silicon nanowires were fabricated by the well-known metal-assisted chemical etching process followed by the deposition of TiO₂ by atomic layer deposition. MoS₂ deposition was achieved through hydrothermal treatment. The MoS₂/TiO₂/SiNW substrate has shown high performance for the detection of small compounds of different molecular weights, including glutathione, glucose, amino acids, antibiotics to name a few. All of the tested compounds, in pure or in mixed solutions were successfully detected in positive ion mode. Therefore, we have also attempted quantitative measurements of GSH and glucose in human blood serum.

Keywords: Glucose; Glutathione detection; LDI-MS; MoS(2) nanosheets; Serum; Silicon nanowires.