MoS2/Ag nanohybrid: A novel matrix with synergistic effect for small molecule drugs analysis by negative-ion matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Abstract

This paper reports a facile synthesis of molybdenum disulfide nanosheets/silver nanoparticles (MoS2/Ag) hybrid and its use as an effective matrix in negative ion matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The nanohybrid exerts a strong synergistic effect, leading to high performance detection of small molecule analytes including amino acids, peptides, fatty acids and drugs. The enhancement of laser desorption/ionization (LDI) efficiency is largely attributed to the high surface roughness and large surface area for analyte adsorption, better dispersibility, increased thermal conductivity and enhanced UV energy absorption as compared to pure MoS2. Moreover, both Ag nanoparticles and the edge of the MoS2 layers function as deprotonation sites for proton capture, facilitating the charging process in negative ion mode and promoting formation of negative ions. As a result, the MoS2/Ag nanohybrid proves to be a highly attractive matrix in MALDI-TOF MS, with desired features such as high desorption/ionization efficiency, low fragmentation interference, high salt tolerance, and no sweet-spots for mass signal. These characteristic properties allowed for simultaneous analysis of eight different drugs and quantification of acetylsalicylic acid in the spiked human serum. This work demonstrates for the first time the fabrication and application of a novel MoS2/Ag hybrid, and provides a new platform for use in the rapid and high throughput analysis of small molecules by mass spectrometry.

A layer-by-layer assembled MoS2 thin film as an efficient platform for laser desorption/ionization mass spectrometry analysis of small molecules

“…2b). 25 The average hydrodynamic radius of the MoS 2 nanoflakes was 87 ± 30 nm (Fig. 1c) The zeta potential value of the MoS 2 nanoflakes was -43.0 ± 1 eV.…”

“…This liquid exfoliation process is simple and efficient for producing colloidal MoS 2 nanoflakes on a large scale. 25 The exfoliated MoS 2 nanoflakes in NMP were then directly transferred into water by a solvent exchange process, with this suspension stable in water for five months without aggregation. The size and thickness of MoS 2 nanoflakes were around 120 ± 30 nm (Fig.…”

“…1). Compared to the previous report, 25 this process is simple, safe and less sensitive to environmental conditions. The prepared colloidal MoS 2 nanoflakes exhibited high efficiency for the LDI-MS analysis of small molecules.…”

“…Recently, Xu et al reported that MoS 2 nanoflakes, prepared by Li intercalation/exfoliation, and the resulting nanocomposites are highly efficient for the LDI-MS analysis of small molecules. 25 However, the previous preparation method is challenging and sensitive to environmental conditions, making simplified chip creation problematic for the widespread applications in LDI-MS analyses.…”

Nanomaterials as Assisted Matrix of Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for the Analysis of Small Molecules

“…Molybdenum disulfide nanosheets/silver NPs (MoS 2 /Ag) nanohybrid was synthesized and used as a matrix of LDI-TOF MS [99]. The as-prepared nanohybride exhibited high performance for analyzing small biological molecules in negative mode.…”