Protein kinase assay on peptide-conjugated gold nanoparticles by using secondary-ion mass spectrometric imaging

(Figure Presented) Spot the mass of peptides: A label-free protein kinase assay that uses secondary-ion mass spectrometric imaging has been demonstrated with peptide-conjugated gold nanoparticles (AuNPs). With detection of the mass change of peptide substrates in a kinase reaction, AuNP-enhanced peptide signals enabled the assaying of both the protein kinase and its inhibition by chemical imaging of peptide substrates on a surface (see picture).