title: Pulse-heating ionization for protein on-chip mass spectrometry.
abstract: An on-chip pulse-heating ionization source for protein samples was developed for the realization of miniaturized mass spectrometry. A protein analyte was ionized on a chip by applying only thermal energy to the solid phase sample without a laser, high voltage, or heated ambient gases. A fabricated ionization source consisting of a Pt/Cr microheater (width: 30 μm; length: 100 μm) on a silicon substrate was coupled with a time-of-flight mass filter to analyze a protein sample of bovine serum albumin (BSA, M = 66 kDa). A singly charged BSA ion and other multiply charged BSA ions were generated in the presence of 2,5-dihydroxybenzoic acid as a matrix. To detect the singly charged BSA ion, the required surface energy density of 1.65 × 10(-2) μJ/μm(2) was applied to the microheater for 500 ns. The use of the 2,5-dihydroxyacetophenone matrix resulted in the generation of the multiply charged protein analyte, while the use of the sinapic acid matrix showed abundant peaks in the low m/z region.
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology (JAIST) , 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Sugiyama
authors.forename: Hiroki
authors.initials: H
authors.lastname: Harako
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ukita
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Shimoda
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Takamura
mesh_terms: D001798:Blood Proteins / Q000032:analysis*; D006358:Hot Temperature; D007477:Ions; D013058:Mass Spectrometry / Q000379:methods*
chemical_list: D001798:Blood Proteins; D007477:Ions