A practical interface for microfluidics and nanoelectrospray mass spectrometry.

Area of Science:

• Analytical Chemistry
• Materials Science
• Microfabrication

Background:

• Conventional nanospray ionization (NSI) emitters can be costly and difficult to fabricate consistently.
• Integration of emitters with microfluidic devices often suffers from dead volumes, impacting separation efficiency.
• There is a need for robust, reproducible, and easily manufactured NSI tips compatible with microfluidic systems.

Purpose of the Study:

• To develop a novel, cost-effective method for fabricating integrated nanospray ionization tips.
• To demonstrate the compatibility of these emitters with microfluidic separations.
• To evaluate the performance of the fabricated emitters with diverse analytes.

Main Methods:

• Fabrication of nanospray ionization tips using photolithography on glass substrates coated with parylene-C.
• Integration of emitters contiguously with microchannels to eliminate dead volumes.
• Characterization of device performance using various analytes including synthetic polymers, peptides, and nucleic acids.

Main Results:

• Successful fabrication of thin (0.3 mm) devices with integrated emitters and microchannels using a single photolithography step.
• Elimination of dead volumes in the fabricated emitter-microchannel system.
• Nanospray ionization performance comparable to conventional emitters for diverse analytes.
• Demonstrated rapid, batch fabrication of identical devices.

Conclusions:

• The developed photolithography method offers a rapid and scalable approach for producing high-performance nanospray ionization tips.
• The integrated design minimizes dead volumes, making it suitable for microfluidic applications.
• These novel emitters provide a cost-effective and reproducible alternative to conventional NSI tips for mass spectrometry.