Surface-Assisted Laser Desorption/Ionization Mass Spectrometry with a Two-Dimensional Au Nanoparticle Array for Soft...

Area of Science:

• Analytical Chemistry
• Surface Science
• Mass Spectrometry

Background:

• Surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is crucial for analyzing small molecules in environmental and medicinal contexts.
• Gold nanoparticles (AuNPs) on SALDI-MS substrates can enhance analyte desorption/ionization through surface plasmon excitation and charge transfer.
• Optimizing energy transfer and minimizing excess internal energy are key to achieving nondissociative detection in SALDI-MS.

Purpose of the Study:

• To investigate and compare the performance of dot-like and 2D-array gold nanoparticle-based SALDI-MS substrates.
• To optimize nondissociative detection of sample molecules by controlling energy transfer during SALDI-MS.
• To understand the influence of substrate morphology on desorption/ionization efficiency and molecular fragmentation.

Main Methods:

• Fabrication and characterization of dot-like and 2D-array gold nanoparticle SALDI-MS substrates.
• SALDI-MS analysis of crystal violet (CV) as a model small molecule.
• Comparative analysis of ion intensity, spectral patterns, and fragmentation between different substrate types.

Main Results:

• Dot-like AuNP substrates showed higher desorption/ionization efficiency but increased molecular fragmentation.
• 2D-array AuNP substrates demonstrated suppressed internal energy supply, leading to less fragmentation.
• 2D-array substrates proved more suitable for highly sensitive and nondissociative SALDI-MS measurements.

Conclusions:

• Substrate morphology significantly impacts energy transfer dynamics and molecular dissociation in SALDI-MS.
• 2D-array gold nanoparticle substrates offer a promising approach for sensitive, non-fragmenting analysis of small molecules.
• This research advances the optimization of SALDI-MS techniques for environmental and medicinal applications.