title: On-plate self-desalting and matrix-free LDI MS analysis of peptides with a surface patterned sample support.
abstract: A hydrophobic-hydrophilic-hydrophobic pattern has been produced on the surface of a silicon substrate for selective enrichment, self-desalting, and matrix-free analysis of peptides in a single step. Upon sample application, the sample solution is first confined in a small area by a hydrophobic F-SAM outer area, after which salt contaminants and peptides are selectively enriched in the hydrophilic and hydrophobic areas, respectively. Simultaneously, matrix background noise is significantly reduced or eliminated because of immobilization of matrix molecules. As a result, the detection sensitivity is enhanced 20-fold compared with that obtained using the usual MALDI plate, and interference-free detection is achieved in the low m/z range. In addition, peptide ions can be identified unambiguously in the presence of NH₄HCO₃ (100 mM), urea (1 M), and NaCl (1 M). When the device was applied to the analysis of BSA digests, the peptide recovery and protein identification confidence were greatly improved.
authors.forename: Zhoufang
authors.initials: Z
authors.lastname: Zeng
authors.forename: Yandong
authors.initials: Y
authors.lastname: Wang
authors.forename: Xinhua
authors.initials: X
authors.lastname: Guo
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.forename: Nan
authors.initials: N
authors.lastname: Lu
mesh_terms: D000804:Angiotensin II / Q000032:analysis / Q000737:chemistry; D000805:Angiotensin III / Q000032:analysis / Q000737:chemistry; D000818:Animals; D001920:Bradykinin / Q000032:analysis / Q000737:chemistry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods; D008970:Molecular Weight; D009842:Oligopeptides / Q000032:analysis* / Q000737:chemistry; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D011492:Protein Hydrolysates / Q000737:chemistry / Q000378:metabolism; D015203:Reproducibility of Results; D012710:Serum Albumin, Bovine / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013499:Surface Properties
chemical_list: D009842:Oligopeptides; D010446:Peptide Fragments; D011492:Protein Hydrolysates; D000804:Angiotensin II; D000805:Angiotensin III; D012710:Serum Albumin, Bovine; D001920:Bradykinin