title: Size-selected (2-10 nm) gold nanoparticles for matrix assisted laser desorption ionization of peptides.
abstract: In this report, first use of size-selected gold nanoparticles (AuNPs) as matrixes for matrix assisted laser desorption/ionization (MALDI) is described for peptides and proteins. In comparison with conventional organic acid MALDI matrixes, the optimum matrix-to-analyte ratio with AuNP matrixes is reduced by 10-14 orders of magnitude. Significant differences in the relative abundances of the ions observed in positive and negative mode MALDI-time-of-flight mass spectrometry (TOFMS) are revealed as the AuNP size distribution is decreased from 10 to 2 nm, whereby 2-nm AuNPs exhibit quantum confinement effects prevalent in quantum dots. AuNP matrixes allow for selective analyte ionization, as demonstrated in the selective MALDI-TOFMS of phosphotyrosine in a background of phosphoserine and phosphothreonine peptides.
authors.affiliation: Laboratory for Biological Mass Spectrometry, Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: McLean
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Stumpo
authors.forename: David H
authors.initials: DH
authors.lastname: Russell
mesh_terms: D006046:Gold / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*; D010748:Phosphopeptides / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009842:Oligopeptides; D010748:Phosphopeptides; D006046:Gold