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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.