Interfacing a polymer-based micromachined device to a nanoelectrospray ionization Fourier transform ion cyclotron resonance mass spectrometer

Here we report the design, fabrication, and operation of a polymer-based mi crochip device interfaced to a nanoelectrospray ionization source and a Fou rier transform ion cyclotron resonance mass spectrometer. The poly(methyl m ethactylate) micromachined device was fabricated using X-ray lithography to produce a network of channels with high aspect ratios. Fabrication of high aspect ratio channels allows for zero dead volume interfaces between the m icrochip platform and the nanoelectrospray capillary interface. The perform ance of this device was evaluated with standard peptide and protein samples . High-quality mass spectral data from peptide and proteins land mixtures t hereof) were obtained without any interfering chemical noise from the polym er or the developers and plasticizers used in the fabrication process. Samp le cross-contamination is not a problem using this polymer-based microchip device as demonstrated by the sequential analysis of several proteins. The nanoelectrospray source was operated at now rates from 20 to 100 nL/min usi ng pressure-driven now, and uninterrupted operation for several hours is de monstrated without any noticeable signal degradation. The ability to fabric ate multiple devices using injection molding or hot-embossing techniques of polymers presides a lower cost alternative to silica-based devices current ly utilized with mass spectrometry.