Remote Detection of Xenon-based Molecular Sensors and the Development of Novel Paramagnetic Agents
2012
Online
Elektronische Ressource
Applications of laser-polarized xenon nuclear magnetic resonance (NMR) spectroscopy and imaging have grown in number due to the exceptional sensitivity of xenon to its local environment. When paired with microfluidic technology, xenon-based molecular sensors (XBMS) have the potential to be used in a broad range of applications from medical devices to geochemistry. Detection of XBMS on a microfluidic chip requires remote detection NMR methodology, where the encoding and detection of aqueous xenon is separated in both space and time. In order to give a clear sense for the state of XBMS with respect to both microfluidics in NMR and magnetic resonance (MR) contrast agents, this thesis provides the background of NMR relevant for performing remote detection NMR experiments, a history of laser-polarized xenon NMR spectroscopy, traditional proton-based magnetic resonance (MR) contrast agents, and the development of XBMS as MR contrast agents.The primary XBMS used in this thesis is a water soluble version of the organic cryptophane-A molecule (cryA). Xenon had been shown to associate with cryA in water with high affinity and relatively fast exchange and cryA can be indirectly detected in low concentrations in solution. A variable previously unexploited in laser-polarized xenon NMR experiments using XBMS was temperature. Temperature is an important parameter in XBMS experiments for generating MR contrast as the affinity for xenon with all soluble versions of cryptophane-A had been shown to increase with increasing temperature and also the exchange of xenon in and out of the cryA was previously shown to increase at higher temperatures. In experiments described in this thesis, temperature was used to increase contrast in both spectroscopic and imaging studies. At 37 C, the threshold for detecting the presence of a negatively charged cryA in solution was decreased to 10 nM - two orders of magnitude lower than what was previously detectable for a positively charged cryA at 25 C.I
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Remote Detection of Xenon-based Molecular Sensors and the Development of Novel Paramagnetic Agents
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Autor/in / Beteiligte Person: | Smith, Monica A. |
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Veröffentlichung: | 2012 |
Medientyp: | Elektronische Ressource |
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