A fluorescence detection scheme for ultra large molecules after gas phase separation

Area of Science:

• Analytical Chemistry
• Biophysics
• Spectroscopy

Background:

• Conventional mass spectrometry faces limitations in analyzing ultra large molecules due to upper mass range restrictions.
• Existing detection methods often exhibit sensitivity that decreases with increasing molecular weight.

Purpose of the Study:

• To develop and demonstrate a mass spectrometry system capable of analyzing ultra large molecules without an upper mass limitation.
• To implement a novel detection scheme that enhances sensitivity for heavy molecules.

Main Methods:

• Ultra large molecules were ionized using electrospray ionization.
• Gas-phase separation of ions was performed using a mass analyzer.
• Laser-induced fluorescence detection was employed instead of traditional electron multipliers.

Main Results:

• The system successfully separated ultra large molecules in the gas phase.
• The laser-induced fluorescence detection scheme demonstrated sensitivity independent of molecular weight.
• Instrument sensitivity was found to correlate with the spectroscopic properties of the molecule's fluorophores.

Conclusions:

• The proposed system effectively removes the upper mass limitation in mass spectrometry for ultra large molecules.
• Laser-induced fluorescence detection offers a viable alternative for sensitive analysis of large biomolecules, irrespective of their mass.