title: Hyperpolarized xenon-based molecular sensors for label-free detection of analytes.
abstract: Nuclear magnetic resonance (NMR) can reveal the chemical constituents of a complex mixture without resorting to chemical modification, separation, or other perturbation. Recently, we and others have developed magnetic resonance agents that report on the presence of dilute analytes by proportionately altering the response of a more abundant or easily detected species, a form of amplification. One example of such a sensing medium is xenon gas, which is chemically inert and can be optically hyperpolarized, a process that enhances its NMR signal by up to 5 orders of magnitude. Here, we use a combinatorial synthetic approach to produce xenon magnetic resonance sensors that respond to small molecule analytes. The sensor responds to the ligand by producing a small chemical shift change in the Xe NMR spectrum. We demonstrate this technique for the dye, Rhodamine 6G, for which we have an independent optical assay to verify binding. We thus demonstrate that specific binding of a small molecule can produce a xenon chemical shift change, suggesting a general approach to the production of xenon sensors targeted to small molecule analytes for in vitro assays or molecular imaging in vivo.
authors: Department of Chemistry and California Institute for Quantitative Biosciences and §Biophysics Graduate Group and California Institute for Quantitative Biosciences, University of California Berkeley , Berkeley, California 94720, United States.
authors: Praveena D
authors: PD
authors: Garimella
authors: Tyler
authors: T
authors: Meldrum
authors: Leah S
authors: LS
authors: Witus
authors: Monica
authors: M
authors: Smith
authors: Vikram S
authors: VS
authors: Bajaj
authors: David E
authors: DE
authors: Wemmer
authors: Matthew B
authors: MB
authors: Francis
authors: Alexander
authors: A
authors: Pines
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D003124:Colorimetry; D015723:Gene Library; D057230:Limit of Detection; D008279:Magnetic Resonance Imaging; D010455:Peptides / Q000737:chemistry* / Q000235:genetics; D013194:Staining and Labeling; D013379:Substrate Specificity; D014978:Xenon / Q000737:chemistry*
chemical_list: D010455:Peptides; D014978:Xenon