共振拉曼光谱在体测量类胡萝卜素含量

类胡萝卜素是人体内重要的抗氧化剂，能够消除体内的自由基和其它有害氧分。研究表明类胡萝卜素含量与癌症、心血管疾病、老化等疾病发病率呈反比关系。目前检测方法为采用血清液相色谱检测方法，不能做到在体无损伤、实时测量。文章介绍了一种用于测量类胡萝卜素的新技术——共振拉曼光谱技术，具有在体无损伤、灵敏度高和实时检测等特点。该技术利用强度远小于美国ANSI Z136.1-2000标准的473 nm激光激发拇指中类胡萝卜素，产生强荧光和叠加在其上的弱共振拉曼光，通过测量拉曼散射光强度在体评估类胡萝卜素的含量。同时，利用组织通透技术，改善了测量信噪比。测量了不同饮食习惯志愿者的类胡萝卜素含量，说明其含量与其摄入量成正比。该技术在临床应用和科学研究等领域具有重要意义。

Carotenoid Levels Measured by Resonance Raman in Vivo

Carotenoid molecules are powerful antioxidants which can act as scavengers for free radicals, singlet oxygen, and other harmful reactive oxygen species in human body. Studies have shown an inverse correlation between the level of carotenoid and the risk of cancers, cardiovascular diseases, and degenerative diseases. High-performance liquid chromatography is used for measuring carotenoid levels as a standard method, but it is not noninvasive and real-time detecting. The authors have developed a novel noninvasive optical technology to measure carotenoid level in vivo by detecting the resonance Raman spectra, which can be used for high sensitivity and real-time detecting. When a low noise 473 nm laser with power less than the exposure limit set by ANSI Z136.1-2000 standards, a clearly distinguishable low resonance Raman spectra superimposed on a strong fluorescence background is produced. The carotenoid level is assessed by measuring the resonance Raman intensity. Using penetrating tissue tech- nology, the authors improved the signal-to-noise ratio in the setup. The experimental results from different volunteers confirmed that the carotenoid level is proportional to the intake of it. The technology provided important values for clinic applications and science research.