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dc.contributor.advisorHanley, Lukeen_US
dc.contributor.authorGasper, Gerald L.en_US
dc.date.accessioned2012-12-07T11:13:26Z
dc.date.available2012-12-07T11:13:26Z
dc.date.created2011-08en_US
dc.date.issued2012-12-07
dc.date.submitted2011-08en_US
dc.identifier.urihttp://hdl.handle.net/10027/8831
dc.description.abstractBiofilms can cause persistent and antibiotic-resistant infections, whose treatment is of major medical concern. Microbial biofilms composed of S. epidermidis are a major source of hospital infections. To address the many questions surrounding bacterial biofilms, MS imaging is needed. MS imaging allowed correlation of chemical information with biologically relevant structures, while maintaining spatial and chemical integrity. Vacuum ultraviolet single photon ionization laser desorption postionization mass spectrometry (LDPI-MS) was used to postionize the abundant gas-phase neutral molecules ejected by laser desorption from bacterial biofilms. LDPI-MS was chemically selective for low ionization energy species, such as antibiotics. Sensitivity was also improved by increasing the neutral desorption yields via addition of a matrix, analogous to the improvement in ion yields observed in MALDI-MS. LDPI-MS with vacuum and extreme ultraviolet radiation from 8 to 24 eV generated at a synchrotron was used to postionize laser desorbed neutrals of antibiotic-treated biofilms and a modified fullerene. LDPI-MS imaging characterized the distribution of antibiotics within intact S. epidermidis bacterial biofilms and displayed heterogeneous features of its microstructure. Spatial resolution of MS imaging experiments of doped biofilms was ~30 microns. Cross sectioning was used to depth profile antibiotics within biofilm slices with depth resolution of ~30 microns. Matrix addition provided nearly a ten fold enhancement of LDPI-MS signal producing limits of detection near 20 fmol.en_US
dc.language.isoenen_US
dc.rightsen_US
dc.rightsCopyright 2011 Gerald L. Gasperen_US
dc.subjectantibioticsen_US
dc.subjectbiofilmen_US
dc.subjectdepth profilingen_US
dc.subjectdesorptionen_US
dc.subjectmatrixen_US
dc.subjectlaser desorptionen_US
dc.subjectMS imagingen_US
dc.subjectpostionizationen_US
dc.subjectvacuum ultravioleten_US
dc.titleMS Imaging of Antibiotics within Staph. epidermidis Bacterial Biofilms by Laser Desorption Postionizationen_US
thesis.degree.departmentChemistryen_US
thesis.degree.disciplineAnalytical Chemistryen_US
thesis.degree.grantorUniversity of Illinois at Chicagoen_US
thesis.degree.levelDoctoralen_US
thesis.degree.namePhD, Doctor of Philosophyen_US
dc.type.genrethesisen_US
dc.contributor.committeeMemberTrenary, Michaelen_US
dc.contributor.committeeMemberKeiderling, Timen_US
dc.contributor.committeeMemberShippy, Scotten_US
dc.contributor.committeeMemberMoore, Jerry F.en_US
dc.type.materialtexten_US


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