A pneumatically assisted nanospray desorption electrospray ionization source for increased solvent versatility and...

Area of Science:

• Analytical Chemistry
• Biochemistry
• Mass Spectrometry

Background:

• Nanospray desorption electrospray ionization (nano-DESI) is a key technique for mass spectrometry imaging (MSI) of biomolecules.
• Current nano-DESI methods require significant sample preparation and matrix application.
• Improvements to the nano-DESI source itself are needed for broader applications.

Purpose of the Study:

• To develop and characterize a novel pneumatically assisted nano-DESI source.
• To enhance sensitivity and versatility in metabolite imaging.
• To reduce reliance on specific probe-to-surface distances and solvent choices.

Main Methods:

• Incorporation of a nebulizer into the conventional nano-DESI setup, replacing the self-aspirating capillary.
• Characterization of the pneumatically assisted nano-DESI device using rat kidney tissue sections.
• Evaluation of sensitivity, solvent versatility, and imaging capabilities.

Main Results:

• The pneumatically assisted nano-DESI device demonstrated a 1-3 order of magnitude increase in sensitivity for metabolite species.
• Improved desolvation and reduced ionization suppression contributed to enhanced sensitivity.
• The device enabled imaging with pure water, facilitating the detection of highly polar endogenous species and reducing dependence on probe-to-surface distance.

Conclusions:

• The developed pneumatically assisted nano-DESI device offers significantly improved sensitivity and versatility for metabolite imaging.
• This advancement allows for higher contrast ion images, enabling more detailed studies of metabolite distribution in biological tissues.
• The technique provides more flexible solvent selection and broader applicability in biochemical and biomedical research.