Wang Yin, Nikodem Michal, Zhang Eric, Cikach Frank, Barnes Jarrod, Comhair Suzy, Dweik Raed A, Kao Christina, Wysocki Gerard
Electrical Engineering Department, Princeton University, Princeton, NJ 08540, USA.
Department of Pathobiology/Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
Sci Rep. 2015 Mar 13;5:9096. doi: 10.1038/srep09096.
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.
测量不同身体腔室中的一氧化氮（NO）和/或其代谢产物改变了我们对生物学的理解。然而，当前的NO测量方法无法考虑天然存在的和实验性的NO同位素，这使得科学界无法完全理解体内的NO代谢。在此，我们展示了一种用于检测NO同位素的中红外法拉第旋转光谱仪（FRS）。该仪器采用了一种新颖的双调制/解调（DM）FRS方法，其噪声性能仅为基本量子散粒噪声水平的2倍，并在同类仪器中提供了创纪录的灵敏度。这是通过一个完全自主、坚固、可运输且不需要低温冷却的系统实现的。DM-FRS能够仅使用45厘米的有效光路，以3.72 ppbv/Hz(1/2) 对(14)NO和0.53 ppbv/Hz(1/2) 对(15)NO的检测限连续监测一氧化氮同位素。这种DM-FRS测量方法可用于提高针对其他自由基物种的传统FRS传感器的性能。证明了该仪器进行与人类NO代谢研究相关测量的可行性。
