Atmospheric molded poly(methylmethacrylate) microchip emitters for sheathless electrospray

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Conventional electrospray ionization emitters often require complex assembly and external connections, increasing dead volume and fabrication complexity.
• Integrating emitters directly onto microfluidic chips is desirable for miniaturization and improved analytical performance.

Purpose of the Study:

• To develop a novel, low-cost fabrication method for disposable sheathless electrospray microchip emitters.
• To demonstrate the utility of these emitters for mass spectrometry-based peptide and protein analysis.

Main Methods:

• Atmospheric molding fabrication protocol using silicon-master/aluminum-spacer/glass-plate molds.
• UV-initiated free radical polymerization of prepolymeric methylmethacrylate solutions.
• On-chip liquid junction design to eliminate external voltage electrode unions.

Main Results:

• Successfully fabricated disposable poly(methylmethacrylate) (PMMA) sheathless electrospray microchip emitters.
• Demonstrated stable electrospray performance for mass spectral measurements of peptides and proteins.
• Achieved reduced dead volume and simplified fabrication without external unions or tip metallization.

Conclusions:

• The developed fabrication route offers a flexible and low-cost method for producing high-stability microchip emitters.
• These emitters facilitate widespread coupling of mass spectrometry to chip-based systems.
• The approach simplifies operation and reduces complexity for microchip electrospray applications.