title: Improved chip design for integrated solid-phase microextraction in on-line proteomic sample preparation.
abstract: A recently introduced silicon microextraction chip (SMEC), used for on-line proteomic sample preparation, has proved to facilitate the process of protein identification by sample clean up and enrichment of peptides. It is demonstrated that a novel grid-SMEC design improves the operating characteristics for solid-phase microextraction, by reducing dispersion effects and thereby improving the sample preparation conditions. The structures investigated in this paper are treated both numerically and experimentally. The numerical approach is based on finite element analysis of the microfluidic flow in the microchip. The analysis is accomplished by use of the computational fluid dynamics-module FLOTRAN in the ANSYS software package. The modeling and analysis of the previously reported weir-SMEC design indicates some severe drawbacks, that can be reduced by changing the microextraction chip geometry to the grid-SMEC design. The overall analytical performance was thereby improved and also verified by experimental work. Matrix-assisted laser desorption/ionization mass spectra of model peptides extracted from both the weir-SMEC and the new grid-SMEC support the numerical analysis results. Further use of numerical modeling and analysis of the SMEC structures is also discussed and suggested in this work.
authors.affiliation: Department of Electrical Measurements, Lund University, Sweden. Thomas.Laurell@elmat.lth.se
authors.forename: Jonas
authors.initials: J
authors.lastname: Bergkvist
authors.forename: Simon
authors.initials: S
authors.lastname: Ekström
authors.forename: Lars
authors.initials: L
authors.lastname: Wallman
authors.forename: Mikael
authors.initials: M
authors.lastname: Löfgren
authors.forename: György
authors.initials: G
authors.lastname: Marko-Varga
authors.forename: Johan
authors.initials: J
authors.lastname: Nilsson
authors.forename: Thomas
authors.initials: T
authors.lastname: Laurell
mesh_terms: D008904:Miniaturization; D010455:Peptides / Q000032:analysis; D040081:Protein Array Analysis / Q000295:instrumentation / Q000379:methods; D020543:Proteome / Q000032:analysis*; D012997:Solvents / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013499:Surface Properties
chemical_list: D010455:Peptides; D020543:Proteome; D012997:Solvents