North Carolina State University
Surface-Assisted Laser Desorption/Ionization-Mass Spectrometry (SALDI-MS) of Controlled Nanofeatures and the Associated Thermal Properties
Abstract
dc:description.abstractSurface-Assisted Laser Desorption/Ionization-Mass Spectrometry (SALDI-MS) utilizes a solid surface as an energy transfer medium for desorption/ionization. The purpose of this research was to generate controlled feature size and distribution so that the proposed mechanisms of desorption/ionization could each be studied in turn. The thermal contribution to desorption/ionization and how it relates to MS response was studied in this segment. In this study, substrates with feature changes from 20 to 60 percent porosity. Peptides, sugars and low molecular weight proteins are used to determine MS performance of the substrates. Pore size and distribution of 100 nm each on Si (0.002-0.005 Ohm/cm) shows the best SALDI-MS signal/noise among those tested. The thermal properties of the substrates were evaluated using thermography in which the temperature changes from different substrates under the same conditions were measured. This measured temperature change was found to be directly related to substrate porosity and MS response. These results confirmed our hypothesis that SALDI-MS is thermally induced and that the increased density of pores on the surface aid in the thermal desorption of the analyte. The optimized substrate generated was used to profile metabolites in a complex biological plant system. Arabidopsis thaliana was transgenically modified with a human inositol 5 phosphatase enzyme and used as a model to test SALDI-MS performance. The small molecules commonly found in the SALDI-MS data include amino acids, organic acids and steroids. Simple sugars required derivatization to increase ionization efficiency. Suppression effects did not allow for the observation of sugar alcohols, even after derivatization.
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
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- Finkel, Nancy Hawkins
- Advisors dc:contributor.advisor
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- Wendy Boss, Committee Member
- Morteza Khaledi, Committee Member
- Lin He, Committee Chair
Subjects
dc:subject × 3Rights
dc:rights- Statement dc:rights
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- I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.
Identifiers
dc:identifier.*- Dc Identifier Other
- etd-07202005-135422