PMMA microfluidic chip
Schematic of the PMMA microfluidic chip bioreactor.

Microfluidic chips are small devices with systems of micrometer sized channels etched into glass, silicon, or molded in plastic. The channels are enclosed by bonding to a flat substrate. Various microfluidic components have been developed to perform valving, mixing, filtering, electrophoresis, liquid chromatography, polymerase chain reaction and other procedures. Sample transport is typically by electroosmosis and/or electrophoresis. In analogy to electronic integrated circuits, multiple components can be combined to form microscale total analysis systems. The advantages of such devices compared to conventional chemical analysis include low cost, small size, low sample consumption, high sensitivity, and rapid analysis.

Rotating Ball Inlet

Rotating ball inlet detail

The rotating ball inlet is a continuous MALDI interface in which the ball transports the matrix and analyte deposit to the laser. The deposition can be done at atmospheric pressure with the ball acting as a vacuum seal.

Capillary Gel Chip

Capillary gel microfluidic chip interfaced to laser desorption/ionization (LDI) mass spectrometry with a time-of-flight mass analyzer.

The capillary gel chip used the infrared laser with no added matrix to desorb and ionize directly from the gel.

Recent Results

Ambient laser ablation sampling for capillary electrophoresis mass spectrometry

Development of an Automated Digestion and Droplet Deposition Microfluidic Chip for MALDI-TOF MS

Ultra sensitive affinity chromatography on avidin-functionalized PMMA microchip for low abundant post-translational modified protein enrichment

A solid-phase bioreactor with continuous sample deposition for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Continuous flow infrared matrix‐assisted laser desorption electrospray ionization mass spectrometry

Development of an efficient on-chip digestion system for protein analysis using MALDI-TOF MS

Microfluidics with MALDI analysis for proteomics

Microfluidic chips for mass spectrometry-based proteomics

On-line versus off-line analysis from a microfluidic device

Interfacing capillary gel microfluidic chips with infrared laser desorption mass spectrometry

Direct coupling of polymer-based microchip electrophoresis to online MALDI-MS using a rotating ball inlet

On-line single droplet deposition for MALDI mass spectrometry