Matrix-free desorption of biomolecules using massive cluster impact

Area of Science:

• Analytical Chemistry
• Biophysics
• Mass Spectrometry

Background:

• Traditional mass spectrometry often requires liquid matrices for sample preparation.
• Achieving high ion yields and minimizing fragmentation from biological samples can be challenging.

Purpose of the Study:

• To investigate the potential of massive-cluster impact (MCI) ionization for analyzing dry biological samples.
• To assess the efficiency of desorption and fragmentation of large biomolecules using MCI.
• To determine the mechanism behind the observed high secondary-ion yields.

Main Methods:

• Utilizing a massive-cluster impact (MCI) beam composed of glycerol clusters.
• Analyzing dry biological samples, including large molecules like cytochrome c.
• Monitoring secondary-ion yields and molecular fragmentation patterns.
• Assessing signal stability during prolonged exposure to the primary beam.

Main Results:

• MCI ionization produced high secondary-ion yields from dry biological samples without a liquid matrix.
• Large molecules, such as cytochrome c, were efficiently desorbed with minimal fragmentation.
• Protonated molecule signals remained intense even after extended primary beam exposure.
• The observed effects were not attributed to glycerol layer buildup.

Conclusions:

• Massive-cluster impact ionization is a viable technique for analyzing dry biological samples.
• MCI offers efficient desorption and reduced fragmentation for large biomolecules.
• The method provides stable and intense signals, overcoming limitations of traditional techniques.