Miniaturized multichannel electrospray ionization emitters on poly(dimethylsiloxane) microfluidic devices.

Area of Science:

• Analytical Chemistry
• Microfluidics
• Mass Spectrometry

Background:

• Electrospray ionization (ESI) is a crucial technique for interfacing liquid samples to mass spectrometry.
• Microfluidic devices offer advantages in sample handling and analysis, but integrating emitters remains challenging.
• Poly(dimethylsiloxane) (PDMS) is a versatile material for fabricating microfluidic systems.

Purpose of the Study:

• To fabricate a novel multichannel electrospray ionization (ESI) emitter integrated within a poly(dimethylsiloxane) (PDMS) microfluidic device.
• To develop a self-alignment system for robust bonding of PDMS microfluidic components.
• To evaluate the performance of the fabricated device for ESI-mass spectrometry analysis of peptides.

Main Methods:

• Fabrication of a 16-channel PDMS microfluidic device using a three-layer photoresist process.
• Integration of 1 mm long emitters with a 60-degree point angle.
• Utilized a self-alignment system for bonding top and bottom PDMS parts.
• Interfaced the device with ESI-mass spectrometry for peptide analysis.

Main Results:

• Successfully fabricated a prototype PDMS microfluidic device with 16 integrated ESI emitters.
• Achieved stable electrospray from the PDMS emitter tips.
• Demonstrated limits of detection under 1 microM for reference peptides, including adrenocorticotropic hormone fragment 1-17, angiotensin I, and III.

Conclusions:

• The developed multichannel PDMS microfluidic device with integrated ESI emitters is effective for interfacing with mass spectrometry.
• The self-alignment system facilitates robust device fabrication.
• The device shows promise for sensitive peptide analysis in ESI-mass spectrometry applications.