Microfabricated PDMS multichannel emitter for electrospray ionization mass spectrometry

Area of Science:

• Analytical Chemistry
• Materials Science
• Microfluidics

Background:

• Electrospray ionization mass spectrometry (ESI-MS) is a crucial technique for molecular analysis.
• Microfabrication offers potential for miniaturized and integrated analytical systems.
• Polydimethylsiloxane (PDMS) is a versatile material for microfluidic device fabrication.

Purpose of the Study:

• To develop and evaluate a novel microfabricated multichannel emitter using PDMS for ESI-MS.
• To assess the performance and durability of PDMS emitters in peptide analysis.
• To demonstrate the integration of microfluidic devices with ESI-MS.

Main Methods:

• Soft lithography was employed to fabricate PDMS multichannel emitters with defined channel dimensions (100 µm x 30 µm).
• Single and four-channel PDMS emitter devices were interfaced with a time-of-flight mass spectrometer.
• The electrospray performance was evaluated using reference peptides (angiotensin I and bradykinin).

Main Results:

• The PDMS emitters demonstrated stable electrospray performance over 30 hours of continuous operation at flow rates of 1-20 µL/min.
• A limit of detection of 1 µM (S/N 18) was achieved for peptide analysis.
• The emitters proved durable under tested conditions, indicating robustness for analytical applications.

Conclusions:

• A novel microfabricated PDMS multichannel emitter for ESI-MS has been successfully implemented.
• The developed emitters offer a durable and sensitive platform for molecular weight determination of peptides.
• This microfabrication approach facilitates the development of integrated microfluidic systems for advanced ESI-MS analyses.