title: Toward the Atomic-Level Mass Analysis of Biomolecules by the Scanning Atom Probe.
abstract: In 1994, a new type of atom probe instrument, named the scanning atom probe (SAP), was proposed. The unique feature of the SAP is the introduction of a small extraction electrode, which scans over a specimen surface and confines the high field, required for field evaporation of surface atoms in a small space, between the specimen and the electrode. Thus, the SAP does not require a sharp specimen tip. This indicates that the SAP can mass analyze the specimens which are difficult to form in a sharp tip, such as organic materials and biomolecules. Clean single wall carbon nanotubes (CNT), made by high-pressure carbon monoxide process are found to be the best substrates for biomolecules. Various amino acids and dipeptide biomolecules were successfully mass analyzed, revealing characteristic clusters formed by strongly bound atoms in the specimens. The mass analysis indicates that SAP analysis of biomolecules is not only qualitative, but also quantitative.
authors.affiliation: 1Kanazawa Institute of Technology,Office of Industry-University Collaboration,7-1 Nonoichi,Ishikawa 921-8501,Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nishikawa
authors.affiliation: 2Department of Applied Chemistry,Kanazawa Institute of Technology,7-1 Nonoichi,Ishikawa 921-8501,Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Taniguchi
mesh_terms: D013058:Mass Spectrometry / Q000379:methods*; D008853:Microscopy / Q000379:methods*; D009930:Organic Chemicals / Q000032:analysis*
chemical_list: D009930:Organic Chemicals
keywords: Scanning atom probe (SAP); amino acid; binding state; biomolecule; carbon nano tube (CNT); dipeptide; quantitative-qualitative analysis