A piezo-ring-on-chip microfluidic device for simple and low-cost mass spectrometry interfacing

Area of Science:

• Analytical Chemistry
• Biotechnology
• Materials Science

Background:

• Microfluidic devices offer precise sample handling for analytical techniques.
• Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a powerful tool for molecular analysis.
• Efficient interfacing of microfluidics with MALDI-MS is crucial for enhanced performance.

Purpose of the Study:

• To develop and evaluate a simple piezo-ring-on-chip microfluidic device for controlled spraying of MALDI-MS targets.
• To integrate a piezoelectric acoustic atomizer into a microfluidic system for sample deposition.
• To assess the device's performance in terms of spraying, matrix crystallization, and peptide detection.

Main Methods:

• Fabrication of a polydimethylsiloxane microfluidic device integrated with a piezo-ring atomizer.
• Evaluation of the device's design, fabrication, actuation, and pulsatile pumping effects.
• Spraying of organic matrix and peptide samples onto MS target substrates using automated and manual deposition.
• Analysis of peptide samples using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS).

Main Results:

• Successful detection of model peptides at concentrations as low as 10^-6 M.
• The piezo-ring-on-chip approach produced finer matrix crystals compared to conventional pipetting.
• Improved MS signal uniformity was observed with the developed microfluidic device.
• The method demonstrated minimal sample consumption.

Conclusions:

• The piezo-ring-on-chip microfluidic device is a simple and effective tool for controlled sample spraying in MALDI-MS.
• This technology enhances matrix crystallization and signal uniformity, leading to improved peptide detection sensitivity.
• The device offers a low-cost, low-sample-consumption alternative to traditional methods for MALDI-MS target preparation.