Femtosecond Infrared Lasers Applied to Fundamental and Bio-imaging Studies in Time-of-flight Secondary Ion Mass Spectrometry
Open Access
Author:
Kucher, Andrew
Graduate Program:
Chemistry
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
April 25, 2014
Committee Members:
Nicholas Winograd, Dissertation Advisor/Co-Advisor Nicholas Winograd, Committee Chair/Co-Chair James Bernhard Anderson, Committee Member Mark Maroncelli, Committee Member Wayne Roger Curtis, Committee Member
Strong field ionization by ultrashort IR pulses was applied to secondary neutral mass spectrometry. The intact post-ionization of a range of molecular structures was observed and protocols for maximizing molecular detection sensitivities were set forth. The technique was successfully applied to some of the largest organic molecules ever detected by any laser post-ionization method, with masses above 500 Da. It was able to produce molecular ion signal intensities that sometimes exceeded those of secondary ions by an order of magnitude. In addition, for the first time ever, strong field ionization secondary neutral mass spectrometry was applied to biological analyses in mouse brain tissues and algal cell colonies where, in some cases, it revealed analytes concealed by matrix ionization effects in the secondary ion mass spectra. Strong field ionization is shown to be a powerful supplement to the TOF-SIMS experiment, and proposed future developments may increase its utility even further.
