无荧光干扰的便携式拉曼光谱仪技术研究

Portable Raman spectrometer shows great potential on chemical, pharmaceutical and food industries. However, the strong fluorescence background of many biochemical materials hinders its large-scale application. The key issues of portable Raman spectrometer which have to be solved are fluorescence rejection and signal-to-noise enhancement. This project will handle these problems starting from the excitation lasers and data processing algorithms of Raman spectroscopy. Firstly, we will design the multi-wavelength laser with narrow spectral width based on diode laser principle, to implement the high output efficiency, all electrical controlled and compact Raman sources. Secondly, we will use the multi-wavelength laser to realize automatic fluorescence rejection with hardware, and study on the highly reliable data processing algorithms with high signal-to-noise ratio, which can not only remove the fluorescence background but also reduce the noise level in the detection results. In addition, we will study the Raman peak extraction method for strong fluorescent samples, and combine the fluorescence rejection technique with surface enhanced Raman spectroscopy (SERS) to realize the Raman analysis of the samples with low concentration and strong fluorescence. This project will improve the technological level of food and drug test, and it will provide powerful support for the large-area promotion of portable Raman testing technology.

便携式拉曼光谱仪在化工、制药、食品安全等领域显现出了巨大的应用潜力，但是生化样品的强荧光背景限制了它的大范围推广。去除荧光干扰、提高信噪比是便携式拉曼仪必须解决的两大关键技术。本项目将从拉曼光谱的激发光源和数据处理算法两方面开展研究：一是基于半导体激光原理，研究多波长输出的窄线宽激光器，实现高输出效率、全电控制、紧凑便携的拉曼光源；二是采用多波长光源研究荧光干扰的硬件自动去除方法，并研究高可靠性、高信噪比的数据处理算法，在去除荧光的同时降低检测结果中的噪声水平。此外我们还将研究强荧光样品的拉曼谱峰提取方法，并且将多波长激发与表面增强技术结合，实现对低浓度、强荧光样品的拉曼检测和分析。本项目的实施将有助于提高我国食品、药品安全的检测水平，为便携式拉曼检测技术的大范围推广提供有力的技术支撑。

便携式拉曼光谱仪有望应用于食品、药品、爆炸物、毒品和环境污染检测等领域，但是强荧光背景会阻碍便携式拉曼光谱仪的进一步推广。本项目提出一种无荧光干扰的便携式拉曼光谱检测方法，主要研究便携式多波长拉曼激发光源，并采用多波长光源研究荧光干扰的硬件自动去除方法，并研究高可靠性、高信噪比的数据处理方法，改善荧光抑制效果，提高拉曼光谱检测信噪比。实现了一种便携式的多波长拉曼光谱激发光源，每个波长的出光功率大于100mW，光谱线宽小于0.3nm。提出了基于多重约束迭代反卷积复原算法的差分拉曼光谱数据复原处理方法，处理所得的拉曼光谱信噪比比原始光谱提高了3倍以上。该方法不但能够完全消除荧光背景的干扰，还能提高检测的信号质量，为便携式拉曼光谱仪在食品、药品、毒品和环境污染物检测领域的应用奠定了基础。