Poly(dimethylsiloxane) microchip: microchannel with integrated open electrospray tip.

A polymer microchip with an open tip for electrospray mass spectrometry is presented. The tip consists of a groove with parallel walls where a droplet can form at the end surface. A lid covers the whole chip except at the microchannel tip, which is left open. Poly(dimethylsiloxane) (PDMS) microchips were cast using a nickel mould which in turn was replicated from a dry etched silicon wafer. Tips with microchannel widths of around 50 microm could easily be replicated. Since the tip had no cover, the assembly of microchip and cover was simplified. A total ion current variation of 5% during 300 s was achieved for a 1 microM myoglobin solution. The non-complex design of the cover makes it suitable for versatile tests of chip prototypes. The nickel mould was found to be useful for PDMS microstructure fabrication. Also, such a robust mould allows casting electrospray tips in more rigid thermoset materials.

[1]  J. Ramsey,et al.  Generating electrospray from microchip devices using electroosmotic pumping. , 1997, Analytical chemistry.

[2]  L. Locascio,et al.  Integrated microfluidic system enabling protein digestion, peptide separation, and protein identification. , 2001, Analytical chemistry.

[3]  B. Karger,et al.  Microfabricated devices for capillary electrophoresis-electrospray mass spectrometry. , 1999, Analytical chemistry.

[4]  J. Henion,et al.  A polymeric microfluidic chip for CE/MS determination of small molecules. , 2001, Analytical chemistry.

[5]  B. Karger,et al.  A microdevice with integrated liquid junction for facile peptide and protein analysis by capillary electrophoresis/electrospray mass spectrometry. , 2000, Analytical chemistry.

[6]  J. Rossier,et al.  Polymer microspray with an integrated thick-film microelectrode. , 2001, Analytical chemistry.

[7]  Séverine Le Gac,et al.  A planar on-chip micro-nib interface for NanoESI-MS microfluidic applications , 2004 .

[8]  R. Aebersold,et al.  A microfabricated device for rapid protein identification by microelectrospray ion trap mass spectrometry. , 1997, Analytical chemistry.

[9]  L. Nyholm,et al.  Sheathless electrospray from polymer microchips. , 2003, Analytical chemistry.

[10]  D. Knapp,et al.  Miniaturized multichannel electrospray ionization emitters on poly(dimethylsiloxane) microfluidic devices , 2001, Electrophoresis.

[11]  Sequential electrospray analysis using sharp-tip channels fabricated on a plastic chip , 2001 .

[12]  Y. Tai,et al.  A micromachined chip-based electrospray source for mass spectrometry. , 2000, Analytical chemistry.

[13]  Jun Kameoka,et al.  An electrospray ionization source for integration with microfluidics. , 2002, Analytical chemistry.

[14]  C. S. Lee,et al.  On-line coupling of micro-enzyme reactor with micro-membrane chromatography for protein digestion, peptide separation, and protein identification using electrospray ionization mass spectrometry. , 2001, Journal of chromatography. A.

[15]  Gwo-Bin Lee,et al.  Poly(dimethylsiloxane)‐based microfluidic device with electrospray ionization‐mass spectrometry interface for protein identification , 2003, Electrophoresis.

[16]  D. Knapp,et al.  Microfabricated PDMS multichannel emitter for electrospray ionization mass spectrometry , 2001, Journal of the American Society for Mass Spectrometry.

[17]  L E Locascio,et al.  Integrated plastic microfluidic devices with ESI-MS for drug screening and residue analysis. , 2001, Analytical chemistry.

[18]  R. Aebersold,et al.  Microfabricated polymer devices for automated sample delivery of peptides for analysis by electrospray ionization tandem mass spectrometry. , 1999, Analytical chemistry.

[19]  P. Zavracky,et al.  Multichannel microchip electrospray mass spectrometry. , 1997, Analytical chemistry.

[20]  S. Quake,et al.  Monolithic microfabricated valves and pumps by multilayer soft lithography. , 2000, Science.

[21]  Yuehe Lin,et al.  Microfabricated isoelectric focusing device for direct electrospray ionization‐mass spectrometry , 2000, Electrophoresis.

[22]  G. Whitesides,et al.  Rapid Prototyping of Microfluidic Systems in Poly(dimethylsiloxane). , 1998, Analytical chemistry.

[23]  D R Knapp,et al.  Microfabrication of polydimethylsiloxane electrospray ionization emitters. , 2001, Journal of chromatography. A.

[24]  R. Aebersold,et al.  Nanoflow solvent gradient delivery from a microfabricated device for protein identifications by electrospray ionization mass spectrometry. , 1998, Analytical chemistry.