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Detection of NO and S- nitrosocompounds using mid-IR CRDS Vitali Stsiapura 1, Vincent K. Shuali 1, Angela Ziegler 1, Kevin K. Lehmann 1, Benjamin M. Gaston.

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Presentation on theme: "Detection of NO and S- nitrosocompounds using mid-IR CRDS Vitali Stsiapura 1, Vincent K. Shuali 1, Angela Ziegler 1, Kevin K. Lehmann 1, Benjamin M. Gaston."— Presentation transcript:

1 Detection of NO and S- nitrosocompounds using mid-IR CRDS Vitali Stsiapura 1, Vincent K. Shuali 1, Angela Ziegler 1, Kevin K. Lehmann 1, Benjamin M. Gaston 2 1 University of Virginia; 2 Case Western Reserve University

2 Biochemistry of NO-containing compounds S-nitrosothiols (RS-NO) receiving attention in biochemistry and medicine as donors of nitric oxide (NO) and nitrosonium (NO + ) - physiologically active molecules involved in signal transduction through transnitrosation of thiol protein groups [1][2] S-nitrosothiol signaling involved in various types of cellular processes, diseases, e.g. cancer, asthma, cystic fibrosis S-nitrosoglutathione, an S-nitrosothiol [1]Lipton. A. J., Nature, 2001 [2]Arnell, D. R., Arch. Biochem. Biophys., 1995

3 NO and S-nitrosothiols UV spectrum of synthetic GSNO [4] [3] Veleeparampil, M., Adv. Phys. Chem., 2009 [4] Balazy, M., J. Biol. Chem., 1998 Wavelength (nm) Absorbance (arb. units)

4 Motivations Present methods of detecting NO (g) (i.e. chemiluminescence) not sensitive enough to measure concentrations released from living cells, at nanomolar levels Ability to differentiate between isotope-labeled NO will allow tracking of NO compounds in cells and biological tissues NO chemiluminescence apparatus [5] [5] USGS Biogeochemistry of Carbon and Nitrogen in Aquatic Environments:

5 Mid-IR Spectroscopic detection of NO 14 NO 15 NO R 1/2 (13/2) for 14 NO R 3/2 (13/2) for 14 NO R 1/2 (37/2) for 15 NO R 1/2 (39/2) for 15 NO Simulated from HITRAN data [6] Frequency (cm -1 ) σ of 14 NO and 15 NO in 100 torr of air ( cm 2 )

6 Cavity Ring-down Spectroscopy Highly reflective mirrors (of 1- R < ) allow light to bounce many times in cavity, whose intensity decays in time at the rate of: Addition of sample with absorption coefficient α(υ)=Nσ(υ) yields: Thus ringdown time is used to measure concentration N IR from laser To detector RD cavity Laser detector

7 Description of External Cavity Quantum Cascade Laser Model: Daylight Solutions mid-IR tunable ec-QCL Tuning range: 70 cm -1 Line width: ~ 6 MHz Peak power to cavity: 38 mW Power (mW) Wavenumber (cm -1 ) [7] NO lines of interest

8 Schematic of setup ec-QCL (Laser) AOM Reference cell InSb detector Internally-coupled Etalon Ring-down cavity isolator InSb detector Mode-matching optics Trigger InSb detector PC- DAQ

9 Cavity Ring-down scheme AOM: R (Gooch & Housego) Laser deflected and freq shifted by AOM to cavity, shut off of AOM in ~ 150 ns 0 th order to reference cell and etalon for frequency calibration Cavity

10 Cavity Ring-down scheme AOM: R (Gooch & Housego) Laser deflected and freq shifted by AOM to cavity, shut off of AOM in ~ 150 ns 0 th order to reference cell and etalon for frequency calibration Cavity

11 Optical isolation CdTe EO crystal, used as ¼ wave plate Returning beam blocked by polarizer HV applied across crystal leads to difference in refractive index between x- and y- polarizations Scan of cavity over 1.2 FSR Cavity modes with isolator Cavity modes w/o isolator time

12 Cavity Apparatus R = (F ~ 12000) ZnSe mirrors with coating (LohnStar) L = 0.35 m V= 350 mL FSR = 430 MHz τ 0 = 4.6 μ s Mirror configuration: Invar plate to fix cavity length Cavity surfaces coated with inert coating (SilcoTek TM ) “Super mirrors” PZTs to scan up to 1.4 cavity FSRs

13 Frequency stabilization Internally coupled Fabry- Perot etalon Dithering of laser line around cavity mode Laser lineCavity mode Frequency [8] [8] Reich, 1986

14 Gas delivery to cavity UV Lamp Flask with GSNO sample He flow 7 μm particle filter Cold trap (LN2 and ethanol slurry) 2 μm particle filter manifold Ring-down cavity Vacuum pump 2.9ppm NO in He tank Legend: NO flow Valve

15 Observed results NO line R 3/2 (13/2) at cm -1 Frequency detuning (MHz) τ (μs)

16 Estimate of limit of detection Allan deviation of k Min σ α : 7.8 × cm -1

17 Isotopic measurement Frequency detuning (GHz)

18 Conclusions Constructed compact RD system able to measure sample concentration in seconds Obtained limit of detection of 30 pptv, exceeding Kosterev’s limit of 0.7ppbv [10], goal to exceed Mürtz’s [11] 7 pptv level Confirmed ability to measure 14 NO and 15 NO levels in same scan [10] Kosterev, A., Appl. Optics, 2001 [11] Heinrich, K., Appl. Phys. B., 2009

19 Future plans [9] [9] Giusfredi, G., Phys. Rev. Letters, 2010

20 Acknowledgments NIH and NSF: financial support Dr. Joseph Hodges (NIST): advice and assistance on cavity length and frequency stabilization

21 References 1.Lipton, Andrew J., et al. "S-nitrosothiols signal the ventilatory response to hypoxia." Nature (2001): Arnelle, Derrick R., and Jonathan S. Stamler. "NO+, NO., and NO− donation by S-nitrosothiols: implications for regulation of physiological functions by S-nitrosylation and acceleration of disulfide formation." Archives of biochemistry and biophysics (1995): Veleeparampil, Manoj M., Usha K. Aravind, and C. T. Aravindakumar. "Decomposition of S-Nitrosothiols Induced by UV and Sunlight." Advances in Physical Chemistry 2009 (2010). 4.Balazy, Michael, et al. "S-Nitroglutathione, a product of the reaction between peroxynitrite and glutathione that generates nitric oxide." Journal of Biological Chemistry (1998): USGS Biogeochemistry of Carbon and Nitrogen in Aquatic Environments: 6.Rothman, Laurence S., et al. "The HITRAN 2004 molecular spectroscopic database." Journal of Quantitative Spectroscopy and Radiative Transfer 96.2 (2005): Daylight Solutions, Inc. 8.M. Reich, et al., Appl. Optics 25, Giusfredi, G., et al. "Saturated-absorption cavity ring-down spectroscopy." Physical review letters (2010): Kosterev, Anatoliy A., et al. "Cavity ringdown spectroscopic detection of nitric oxide with a continuous- wave quantum-cascade laser." Applied optics (2001): Heinrich, K., et al. "Infrared laser-spectroscopic analysis of 14NO and 15NO in human breath." Applied Physics B 95.2 (2009):

22 Statistics Transverse spacing: MHz Pressure broadening: ~ 2.6 MHz/torr (self), ~ 2.2 MHz/torr (He) Transit time broadening: 180 kHz Etalon FSR: 750 MHz SNR of detector, sensitivity, etc. Thermal drift stuff

23 Gas delivery to cavity UV Photolysis Lamp Cold Trap (LN2 + ethanol) 3 Å Molecular Sieve He flow NO in He 2 μm particle filter To RD cell

24 Saturation Example Lamb dip [10] Lamb-dip Doppler- broadened line [9] [9] Giusfredi, 2010 [10] Taubman, 2004

25 Stabilization of cavity length HeNe AOM Frequency Comb IR Laser Look at beat freq Ring-down detector freq PDH Ideal beat freq Actual beat deviation freq PZT Ring-down cavity


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