Matrix-free LDI mass spectrometry platform using patterned nanostructured gold thin film.

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Surface Science

Background:

• Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is a common technique for analyzing biomolecules.
• The use of matrices in MALDI-MS can lead to ion suppression and interfere with sensitive analyses.
• Developing matrix-free ionization techniques is crucial for improving MS sensitivity and simplifying sample preparation.

Purpose of the Study:

• To present a novel matrix-free laser direct ionization (LDI) mass spectrometry (MS) platform.
• To evaluate the performance of this platform for peptide analysis and protein identification.
• To demonstrate the versatility of the developed LDI substrate.

Main Methods:

• Fabrication of a thin film of patterned nanostructured gold.
• Functionalization of the gold surface with methyl- and carboxy-terminated self-assembled monolayers (SAMs).
• Mass spectrometry analysis including limit of detection, peptide mass fingerprinting, and small molecule analysis.

Main Results:

• The matrix-free LDI MS platform demonstrated successful calibration and sensitive detection of peptides.
• Peptide mass fingerprinting analysis of protein digests showed comparable or improved results to conventional MALDI MS.
• The platform exhibited versatility by analyzing protein digests with different enzymes and performing small molecule analysis.

Conclusions:

• The novel nanostructured gold LDI MS platform offers a promising matrix-free alternative for sensitive peptide and protein analysis.
• The developed substrate provides a versatile and effective surface for various mass spectrometry applications.
• This approach simplifies sample preparation and enhances analytical performance in mass spectrometry.