title: Shot-noise limited Faraday rotation spectroscopy for detection of nitric oxide isotopes in breath, urine, and blood.
abstract: Measurement of NO and/or its metabolites in the various body compartments has transformed our understanding of biology. The inability of the current NO measurement methods to account for naturally occurring and experimental NO isotopes, however, has prevented the scientific community from fully understating NO metabolism in vivo. Here we present a mid-IR Faraday rotation spectrometer (FRS) for detection of NO isotopes. The instrument utilizes a novel dual modulation/demodulation (DM) FRS method which exhibits noise performance at only 2 times the fundamental quantum shot-noise level and provides the record sensitivity in its class. This is achieved with a system that is fully autonomous, robust, transportable, and does not require cryogenic cooling. The DM-FRS enables continuous monitoring of nitric oxide isotopes with the detection limits of 3.72 ppbv/Hz(1/2) to(14)NO and 0.53 ppbv/Hz(1/2) to(15)NO using only 45 cm active optical path. This DM-FRS measurement method can be used to improve the performance of conventional FRS sensors targeting other radical species. The feasibility of the instrument to perform measurements relevant to studies of NO metabolism in humans is demonstrated.
authors.affiliation: Electrical Engineering Department, Princeton University, Princeton, NJ 08540, USA.
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Electrical Engineering Department, Princeton University, Princeton, NJ 08540, USA.
authors.forename: Michal
authors.initials: M
authors.lastname: Nikodem
authors.affiliation: Electrical Engineering Department, Princeton University, Princeton, NJ 08540, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Zhang
authors.affiliation: Department of Pathobiology/Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Cikach
authors.affiliation: Department of Pathobiology/Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
authors.forename: Jarrod
authors.initials: J
authors.lastname: Barnes
authors.affiliation: Department of Pathobiology/Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
authors.forename: Suzy
authors.initials: S
authors.lastname: Comhair
authors.affiliation: 1] Department of Pathobiology/Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA [2] Pulmonary and Critical Care Medicine/Respiratory Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
authors.forename: Raed A
authors.initials: RA
authors.lastname: Dweik
authors.affiliation: Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Kao
authors.affiliation: Electrical Engineering Department, Princeton University, Princeton, NJ 08540, USA.
authors.forename: Gerard
authors.initials: G
authors.lastname: Wysocki
mesh_terms: D045853:Exhalation; D006801:Humans; D007554:Isotopes; D009569:Nitric Oxide / Q000097:blood / Q000378:metabolism* / Q000652:urine; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*
chemical_list: D007554:Isotopes; D009569:Nitric Oxide