Fibre optic probe based Raman spectroscopy can deliver in vivo molecular compositional analysis of a range of diseases. However, some biological tissues exhibit high levels of fluorescence which limit the utility of the technique, particularly when the fluorescence induces CCD etaloning, which can be particulalry hard to remove in subsequent analysis. Furthermore, use of fibre probes can result in silica signals superimposed on the biological Raman signals. Shifted excitation Raman difference spectroscopy (SERDS) utilises a small seperation in excitation wavelengths to remove signals from fluorescence, room lights, optical components and etaloning contributions, while retaining chemical signals from the sample. In this study, we sought to measure the optimum SERDS spectra enabling reconstruction of a range a narrow and broad peaks found in biological samples. A original wavelength of 830 nm was utilised with 7 different shifts between 0.4 and 3.9 nm to determine which gave the best performance. This range roughly corresponds to the typical range of peak widths within biological Raman spectra at 830 nm excitation; 0.41 – 3.25 nm or 6 – 47 cm⁻¹. An wavelength shift of 2.4 nm was identified as optimal. Finally, a fibre optic Raman probe was used to measure 2 human lymph nodes ex vivo to demonstrate the feasibility of the approach with real-world examples.

中文翻译：

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使用光纤探针优化移位激发拉曼差谱 （SERDS），以应用于高荧光生物样品


基于光纤探针的拉曼光谱可以对一系列疾病进行体内分子组成分析。然而，一些生物组织表现出高水平的荧光，这限制了该技术的实用性，特别是当荧光诱导 CCD etaloning 时，这在后续分析中可能难以去除。此外，使用光纤探针会导致二氧化硅信号叠加在生物拉曼信号上。位移激发拉曼差谱 （SERDS） 利用激发波长的少量分离来去除荧光、室内光、光学元件和激发贡献的信号，同时保留样品中的化学信号。在这项研究中，我们试图测量最佳的 SERDS 光谱，从而能够重建生物样品中发现的窄峰和宽峰范围。使用 830 nm 的原始波长和 0.4 和 3.9 nm 之间的 7 个不同偏移来确定哪个具有最佳性能。该范围大致对应于生物拉曼光谱中 830 nm 激发时的典型峰宽范围;0.41 – 3.25 nm 或 6 – 47 cm⁻¹。2.4 nm 的波长偏移被确定为最佳波长。最后，使用光纤拉曼探头在离体测量 2 个人类淋巴结，以通过真实世界示例证明该方法的可行性。