本研究建置了一套新型拉曼光譜量測系統，結合位移激發拉曼差分光譜技術(SERDS)與反射式拉曼探頭(RRP)，有效地解決了在拉曼光譜分析中常見的背景訊號干擾問題，並提高了拉曼特徵峰的訊噪比，使光譜數據的判讀更為清晰與準確。
位移激發拉曼差分光譜技術(SERDS)是一種有效區分拉曼特徵訊號與背景訊號的方法，透過兩個略微位移的雷射激發波長，在同個樣品位置連續獲取兩張光譜圖，經過SERDS演算法重建後得到沒有背景干擾的拉曼光譜圖。比較了三種扣除背景訊號的方法，結果發現經過SERDS重建的光譜結果不會受到外界光源的影響。同時，比較了原始光譜與重建光譜的光譜結果，發現重建光譜不僅保留了原始光譜的光譜特性(半高寬)，並且在訊噪比上也有了顯著的提升，即使在強大的螢光或環境光背景訊號干擾下，一樣可以透過重建後的拉曼光譜觀察樣品的拉曼訊號。
在具體應用中，成功辨識了毒奶粉中的三聚氰胺、含有非法添加物蘇丹紅1號的辣椒粉，以及夾鏈袋中的PE塑膠與其使用的染料成分。另外，透過量測不同重量百分比濃度的樣品，建立濃度曲線圖，說明自建的量測系統可以進行定性且定量的量測分析。展示了該量測系統在實際應用的實用性。此外本系統硬體沿用實驗室蔡凱鈞學長開發的多波長反射式探頭的光路，並與784/785 nm雙波長雷射結合實現反射式-位移激發拉曼差分光譜系統(r-SERDS)。本系統可消除螢光背景干擾，並保有低能量密度、高入射光與光譜收光效率的特性。其大雷射光斑的設計除了可容許較高的雷射激發能量換取更好的訊號強度，也可以解決待測物分布不均或SERS基板上微結構尺寸不均勻造成拉曼光譜量測強度不一的問題。
本研究建置的新型拉曼光譜量測系統，不僅提高了拉曼光譜分析的準確性和量測效率，搭配反射式探頭的使用針對具有能量閥值上限、具有強烈螢光背景樣品以及受限的量測環境都可進行正確且快速的量測。

This study has developed a new Raman spectroscopy measurement system that combines Shifted Excitation Raman Difference Spectroscopy (SERDS) with a Reflective Raman Probe (RRP). This effectively addresses the common issue of background signal interference in Raman spectroscopy analysis and improves the signal-to-noise ratio (SNR) of Raman characteristic peaks, making the spectral data interpretation clearer and more accurate.
Shifted Excitation Raman Difference Spectroscopy (SERDS) is an effective method for distinguishing Raman characteristic signals from background signals. By using two slightly shifted laser excitation wavelengths to acquire two spectra at the same sample location continuously, SERDS reconstructs Raman spectra that have the background signals subtracted, leaving only the pure Raman characteristic peaks of the sample. Three methods for subtracting background signals were compared, and the results showed that the spectra reconstructed through SERDS were not affected by external light sources. By comparing the original spectra with the reconstructed spectra obtained through SERDS, it was found that they not only retained the spectral characteristics (FWHM) of the original spectra but also significantly improved the SNR. Even under strong fluorescence or environmental light background signal interference, the Raman signals of the samples can still be observed through the reconstructed Raman spectra.
In practical applications, the system successfully identified melamine in contaminated milk powder, Sudan I in adulterated chili powder, and the components of PE plastic and its dye in zipper bags. Additionally, by measuring samples with different weight percentages, a concentration curve was established, demonstrating that the measurement system can perform both qualitative and quantitative analysis. This showcases the practicality of the measurement system in real-world applications.
Moreover, the hardware of this system adopts the optical path of the multi-wavelength reflective Raman probe developed by former lab member Tsai Kai-Jiun and combines it with a 784/785 nm dual-wavelength laser to achieve a reflective Shifted Excitation Raman Difference Spectroscopy system (r-SERDS). This setup can eliminate fluorescence background interference and maintain characteristics such as low energy density, high incident light efficiency, and efficient spectral collection. The design of a large laser spot allows for higher laser excitation energy to achieve better signal intensity and solves the problem of inconsistent Raman measurement intensities caused by uneven analyte distribution or uneven microstructure sizes on SERS substrates.
The new Raman spectroscopy measurement system established in this study not only improves the accuracy and efficiency of Raman spectroscopy analysis but also, with the use of the reflective probe, enables accurate and rapid measurements in samples with energy threshold limits, strong fluorescence backgrounds, and restricted measurement environments.

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