Matrix-free laser desorption/ionization-mass spectrometry using self-assembled germanium nanodots

Anal Chem. 2007 Jul 1;79(13):4827-32. doi: 10.1021/ac062216a. Epub 2007 Jun 2.

Abstract

A novel ionization platform for matrix-free laser desorption/ionization-mass spectrometry (LDI-MS) was developed using self-assembled germanium nanodots (GeNDs) of uniform size (approximately 150 - 200-nm width and approximately 50-nm height) grown on a silicon wafer produced by molecular beam epitaxy. The performance of LDI-MS using GeNDs (GeND-MS) was investigated through measurements of a broad range of analytes, including peptides, proteins, synthetic oligomers, and polymer additives. Mass spectra of tryptic digests were clearly observed even for the mass range lower than m/z 800 without obstructive peaks. A detection limit of subfemtomole level was achieved for angiotensin-I. The upper limit of detectable mass range was approximately 17 kDa (myoglobin). GeND-MS also has potential for application to the characterization of industrial compounds. Almost accurate molecular weight distribution was obtained for a nonionic surfactant (Triton X-100) and for poly(ethylene glycol) oligomer. Furthermore, a brominated flame retardant, tetrabromobisphenol-A bis(2,3-dibromopropyl ether), was successfully ionized with less fragmentation, a result not obtainable by matrix-assisted laser desorption/ionization-mass spectrometry or desorption/ionization on porous silicon-mass spectrometry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin I / analysis
  • Flame Retardants / analysis
  • Germanium / chemistry*
  • Humans
  • Lasers*
  • Light
  • Molecular Weight
  • Myoglobin / analysis
  • Nanostructures / chemistry*
  • Octoxynol / analysis
  • Polybrominated Biphenyls / analysis
  • Polyethylene Glycols / analysis
  • Sensitivity and Specificity
  • Silicon / chemistry*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Surface-Active Agents / analysis
  • Trypsin / metabolism

Substances

  • Flame Retardants
  • Myoglobin
  • Polybrominated Biphenyls
  • Surface-Active Agents
  • Germanium
  • Polyethylene Glycols
  • Octoxynol
  • Angiotensin I
  • Trypsin
  • tetrabromobisphenol A
  • Silicon