Abstract
Fluorescence spectroscopy and mass spectrometry have been extensively used for characterization of biomaterials, but usually separately. An instrument combining fluorescence spectroscopy and Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS) has been developed to explore both fluorescence and mass spectrometric behavior of ions produced by electrospray ionization (ESI) in ultra high vacuum (<5 × 10−9 mbar). Using rhodamine 6G (R6G) as a sample, the instrument was systematically characterized. Gas-phase fluorescence and mass spectral signal of the same ion population are detected immediately after each other. Effects of gas pressure, ion density, and excitation laser power on the fluorescence signal intensity and mass spectral fragmentation patterns are discussed. Characteristic times of ion photodissociation in ultra high vacuum were recorded for different irradiation powers. Photofragmentation patterns of rhodamine 6G ions in the Penning trap of an FTICR spectrometer obtained by photoinduced dissociation (PID) with visible light and sustained off-resonance irradiation collision-induced dissociation (SORI-CID) were compared. The lowest energy dissociation fragment of rhodamine 6G ions was identified by relating PID patterns of rhodamine 6G and rhodamine 575 dyes at various irradiation powers. The unique instrument provides a powerful platform for probing the intramolecular relaxation mechanisms of nonsolvated ions when interacting with light, which is of great fundamental interest for better understanding of their physical and chemical properties.
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References
Valeur, B. Molecular Fluorescence: Principles and Applications; Wiley-VCH: Weinheim, 2002, 11–15, 41.
Wang, Y.; Hendrickson, C. L.; Marshall, A. G. Direct Optical Spectroscopy of Gas-Phase Molecular Ions Trapped and Mass-Selected by Ion Cyclotron Resonance: Laser-Induced Fluorescence Excitation Spectrum of Hexafluorobenzene (C6F6+). Chem. Phys. Lett. 2001, 1/3, 69–75.
Khoury, J. T.; Rodriguez-Cruz, S. E.; Parks, J. H. Pulsed Fluorescence Measurements of Trapped Molecular Ions with Zero Background Detection. J. Am. Soc. Mass Spectrom 2002, 6, 696–708.
Wright, K. C.; Blades, M. W. Fluorescence Emission Spectroscopy of Trapped Molecular Ions. Proceedings of the 51st ASMS Conference on Mass Spectrometry and Allied Topics; Montreal, Canada, June, 2003.
Frankevich, V.; Guan, X. W.; Dashtiev, M.; Zenobi, R. Laser-Induced Fluorescence of Trapped Gas-Phase Molecular Ions Generated by Internal-Source Matrix-Assisted Laser Desorption/Ionization in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer. Eur. J. Mass Spectrom 2005, 5, 475–482.
Bian, Q.; Talbot, F. O.; Forbes, M. W.; Yao, H.; Jockusch, R. A. Development and Characterization of Laser Induced Fluorescence Spectroscopy Coupled with Ion Trap Mass Spectrometry. Proceedings of the 56th ASMS Conference on Mass Spectrometry and Allied Topics; Denver, CO, June, 2008.
Sassin, N. A.; Everhart, S. C.; Dangi, B. B.; Ervin, K. M.; Cline, J. I. Fluorescence and Photodissociation of rhodamine 575 Cations in a Quadrupole Ion Trap. J. Am. Soc. Mass Spectrom 2009, 1, 96–104.
Fenn, J. B.; Mann, M.; Meng, C. K.; Wong, S. F.; Whitehouse, C. M. Electrospray Ionization for Mass-Spectrometry of Large Biomolecules. Science 1989, 4926, 64–71.
Hillenkamp, F.; Karas, M.; Beavis, R. C.; Chait, B. T. Matrix-Assisted Laser Desorption Ionization Mass-Spectrometry of Biopolymers. Anal. Chem. 1991, 24, A1193-A1202.
Stryer, L.; Haugland, R. P. Energy Transfer—A Spectroscopic Ruler. Proc. Natl. Acad. Sci. U.S.A. 1967, 2, 719–726.
Danell, A. S.; Parks, J. H. FRET Measurements of Trapped Oligonucleotide Duplexes. Int. J. Mass Spectrom 2003, 1/2, 35–45.
Iavarone, A. T.; Parks, J. H. Conformational Change in Unsolvated Trp-Cage Protein Probed by Fluorescence. J. Am. Chem. Soc. 2005, 24, 8606–8607.
Neuweiler, H.; Sauer, M. Using Photoinduced Charge Transfer Reactions to Study Conformational Dynamics of Biopolymers at the Single-Molecule Level. Curr. Pharm. Biotechnol. 2004, 3, 285–298.
Iavarone, A. T.; Duft, D.; Parks, J. H. Shedding Light on Biomolecule Conformational Dynamics Using Fluorescence Measurements of Trapped Ions. J. Phys. Chem. A 2006, 47, 12714–12727.
Marshall, A. G.; Hendrickson, C. L.; Jackson, G. S. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry: A primer. Mass Spectrom. Rev. 1998, 1, 1–35.
Li, G. Z.; Vining, V. A.; Guan, S. H.; Marshall, A. G. Laser-Induced Fluorescence of Ba+ Ions Trapped and Mass-Selected in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer. Rapid Commun. Mass Spectrom. 1996, 14, 1850–1854.
Dashtiev, M.; Azov, V.; Frankevich, V.; Scharfenberg, L.; Zenobi, R. Clear Evidence of Fluorescence Resonance Energy Transfer in Gas-Phase Ions. J. Am. Soc. Mass Spectrom 2005, 9, 1481–1487.
Abraham, E. R. I.; Cornell, E. A. Teflon Feedthrough for Coupling Optical Fibers into Ultrahigh Vacuum Systems. Appl. Optics 1998, 10, 1762–1763.
Guan, S. H.; Marshall, A. G. Ion Traps for Fourier-Transform Ion-Cyclotron Resonance Mass-Spectrometry—Principles and Design of Geometric and Electric Configurations. Int. J. Mass Spectrom. Ion Processes 1995, 146, 261–296.
Dashtiev, M.; Zenobi, R. Effect of Buffer Gas on the Fluorescence Yield of Trapped Gas-Phase Ions. J. Am. Soc. Mass Spectrom. 2006, 6, 855–858.
Eggeling, C.; Widengren, J.; Rigler, R.; Seidel, C. A. M. Photobleaching of Fluorescent Dyes Under Conditions Used for Single-Molecule Detection: Evidence of Two-Step Photolysis. Anal. Chem. 1998, 13, 2651–2659.
Gauthier, J. W.; Trautman, T. R.; Jacobson, D. B. Sustained Off-Resonance Irradiation for Collision-Activated Dissociation Involving Fourier-Transform Mass-Spectrometry-Collision-Activated Dissociation Technique That Emulates Infrared Multiphoton Dissociation. Anal. Chim. Acta 1991, 1, 211–225.
Little, D. P.; Speir, J. P.; Senko, M. W.; O’Connor, P. B.; McLafferty, F. W. Infrared Multiphoton Dissociation of Large Multiply-Charged Ions for Biomolecule Sequencing. Anal. Chem. 1994, 18, 2809–2815.
Guan, S. H.; Marshall, A. G.; Wahl, M. C. MS/MS with High Detection Efficiency and Mass Resolving Power for Product Ions in Fourier-Transform Ion-Cyclotron Resonance Mass-Spectrometry. Anal. Chem. 1994, 8, 1363–1367.
Williams, E. R.; Furlong, J. J. P.; McLafferty, F. W. Efficiency of Collisionally-Activated Dissociation and 193-nm Photodissociation of Peptide Ions in Fourier-Transform Mass-Spectrometry. J. Am. Soc. Mass Spectrom. 1990, 4, 288–294.
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Published online May 29, 2009
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Chingin, K., Chen, H., Gamez, G. et al. Exploring fluorescence and fragmentation of ions produced by electrospray ionization in ultrahigh vacuum. J Am Soc Mass Spectrom 20, 1731–1738 (2009). https://doi.org/10.1016/j.jasms.2009.05.011
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DOI: https://doi.org/10.1016/j.jasms.2009.05.011