Graphene Oxide as a Novel Evenly Continuous Phase Matrix for TOF-SIMS

Area of Science:

• Surface Science
• Analytical Chemistry
• Biotechnology

Background:

• Matrix crystallization in Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) hinders biomolecule identification and spatial resolution in biological research.
• Enhancing molecular ion signals without compromising spatial integrity is crucial for TOF-SIMS applications in complex biological samples.

Purpose of the Study:

• To investigate graphene oxide (GO) as a novel matrix for TOF-SIMS to improve secondary ion yields of intact molecular ions.
• To assess the impact of GO on spatial resolution and the identification of high mass lipids (m/z >700) in biological samples.
• To demonstrate the capability of GO-assisted TOF-SIMS for high-resolution lipid mapping and distinguishing vesicles based on chemical composition.

Main Methods:

• Graphene oxide (GO) was employed as a matrix material for TOF-SIMS analysis.
• TOF-SIMS imaging was performed on biological samples utilizing the GO matrix.
• Analysis focused on improving secondary ion yields, particularly for intact molecular ions ([M + H]+) of lipids (m/z >700).

Main Results:

• Graphene oxide significantly enhanced secondary ion yields for intact molecular ions, simplifying lipid identification.
• GO facilitated homogeneous matrix layer formation, preserving high spatial resolution in TOF-SIMS imaging.
• Lipid mapping with GO revealed detailed morphology and distribution of 800 nm vesicles, distinguishing them by chemical composition.

Conclusions:

• Graphene oxide serves as an effective matrix for TOF-SIMS, enhancing biomolecule signal detection and maintaining spatial resolution.
• This GO-based approach enables straightforward identification and mapping of lipids in complex biological samples.
• The developed method shows significant potential for advanced analysis and imaging of biological systems using TOF-SIMS.