Surface-assisted laser desorption and ionization mass spectrometry using low-cost matrix-free substrates

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Surface-assisted laser desorption/ionization (SALDI) is a mass spectrometry technique requiring specialized substrates.
• Developing cost-effective and reproducible SALDI substrates is crucial for widespread analytical applications.
• Femtosecond laser ablation and soft nanolithography offer pathways for creating nanostructured materials.

Purpose of the Study:

• To fabricate novel nanospiked polyurethane (PU) substrates for SALDI applications.
• To investigate the effectiveness of these PU substrates in enhancing mass spectrometry signals.
• To assess the reproducibility and potential applications of the developed SALDI substrates.

Main Methods:

• Fabrication of silicon nanospike structures using femtosecond laser irradiation.
• Replication of nanospike structures onto polyurethane using low-cost soft nanolithography.
• Coating nanospiked PU substrates with gold nanoparticles (45-nm thickness).
• Analysis of Angiotensin II using mass spectrometry (MS) on the fabricated substrates.

Main Results:

• Successfully fabricated nanospiked PU substrates via a cost-effective soft nanolithography method.
• Achieved the strongest mass spectrometry signal for Angiotensin II on 45-nm gold-coated nanospiked PU substrates.
• Observed effective ionization attributed to surface plasmon excitation.
• Demonstrated high reproducibility in MS analysis using the developed SALDI substrates.

Conclusions:

• Low-cost, nanospiked PU substrates can be effectively fabricated for SALDI-MS.
• Gold-coated nanospiked PU substrates significantly enhance MS signal intensity.
• These substrates offer a reproducible and versatile platform for the mass spectrometry analysis of diverse molecules.