Fluorinated Gold Nanoparticles for Nanostructure Imaging Mass Spectrometry

Area of Science:

• Analytical Chemistry
• Biochemistry
• Materials Science

Background:

• Nanoparticle-assisted laser desorption/ionization (NALDI) techniques are crucial for sensitive molecular analysis.
• Existing methods can suffer from high laser energy requirements, leading to analyte fragmentation and limited metabolome coverage.
• Developing gentle, high-sensitivity methods for comprehensive tissue metabolomics is essential.

Purpose of the Study:

• To introduce and validate Nanostructure Imaging Mass Spectrometry (NIMS) utilizing fluorinated gold nanoparticles (f-AuNPs) for comprehensive metabolite analysis in biological tissues.
• To demonstrate the low laser energy requirements and high sensitivity of the f-AuNP NIMS approach.
• To showcase the ability of f-AuNP NIMS to provide broad metabolome coverage and preserve molecular integrity.

Main Methods:

• Utilized fluorinated gold nanoparticles (f-AuNPs) for nanoparticle-assisted laser desorption/ionization.
• Employed low laser energy (μJ/pulse range) to minimize in-source metabolite fragmentation.
• Applied perfluorohexane for f-AuNP distribution, creating a hydrophobic environment to prevent metabolite solubilization and dislocation.
• Analyzed mouse colon tissue samples from different dietary groups.

Main Results:

• f-AuNP NIMS demonstrated high sensitivity and required low laser energy, minimizing background noise.
• Electron microscopy confirmed a gentle desorption mechanism with minimal tissue surface alteration compared to traditional MALDI.
• The method enabled direct detection of a wide range of metabolites including carbohydrates, lipids, bile acids, amino acids, and nucleotide precursors.
• Heterogeneous metabolome coverage was achieved, providing a broad picture of tissue metabolic organization.

Conclusions:

• NIMS with f-AuNPs is a powerful, sensitive, and gentle technique for comprehensive tissue metabolomics.
• The f-AuNP NIMS approach overcomes limitations of high laser energy and analyte fragmentation, enabling broader metabolite detection.
• This method provides valuable insights into tissue metabolic organization and responses to dietary changes.