Mass Spectrometric Identification of Proteins Enhanced by the Atomic Force Microscopy Immobilization Surface

Int J Mol Sci. 2021 Jan 4;22(1):431. doi: 10.3390/ijms22010431.

Abstract

An approach to highly-sensitive mass spectrometry detection of proteins after surface-enhanced concentrating has been elaborated. The approach is based on a combination of mass spectrometry and atomic force microscopy to detect target proteins. (1) Background: For this purpose, a technique for preliminary preparation of molecular relief surfaces formed as a result of a chemical or biospecific concentration of proteins from solution was developed and tested on several types of chip surfaces. (2) Methods: mass spectrometric identification of proteins using trailing detectors: ion trap, time of flight, orbital trap, and triple quadrupole. We used the electrospray type of ionization and matrix-assisted laser desorption/ionization. (3) Results: It is shown that when using locally functionalized atomically smooth surfaces, the sensitivity of the mass spectrometric method increases by two orders of magnitude as compared with measurements in solution. Conclusions: It has been demonstrated that the effective concentration of target proteins on specially prepared surfaces increases the concentration sensitivity of mass spectrometric detectors-time-of-flight, ion trap, triple quadrupole, and orbital ion trap in the concentration range from up to 10-15 M.

Keywords: atomic force microscope; mass spectrometry; protein detection; smooth chip.

MeSH terms

  • Humans
  • Microscopy, Atomic Force / methods*
  • Proteins / analysis*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Surface Properties

Substances

  • Proteins