Raman spectroscopy is widely applied in wood science because of its features of being nondestructive, rapidity, and high resolution. However, Raman scattering is weak, and the Raman signal is easily disturbed by autofluorescence arising from endogenous fluorescent molecules in biological tissue. In this work, a sensitive lignin detection platform was fabricated by a composite with a polyaniline (PANI) nanofiber and toluidine blue (TB) under the excitation of visible light. In this platform, TB acts as a specific marker for lignin, and a PANI nanofiber was used as a reinforcing reagent to improve the Raman intensity of TB. When wood slice is impregnated with TB/PANI, the lignin in wood can be precisely labeled with the TB, and the Raman intensity of TB had a threefold increase at 532 nm excitation. This TB/PANI detection platform is expected to make a significant contribution in qualitative and quantitative analysis of lignin to avoid autofluorescence in various lignin-based biosciences.

中文翻译：

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一种新型聚苯胺纳米纤维与甲苯胺蓝相结合作为木质素的拉曼光谱灵敏检测平台

拉曼光谱以其无损、快速、高分辨率等特点在木材科学中得到广泛应用。然而，拉曼散射较弱，拉曼信号容易受到生物组织中内源性荧光分子产生的自发荧光的干扰。在这项工作中，在可见光的激发下，由聚苯胺 (PANI) 纳米纤维和甲苯胺蓝 (TB) 的复合材料制造了灵敏的木质素检测平台。在该平台中，TB 作为木质素的特异性标记物，PANI 纳米纤维用作增强剂以提高 TB 的拉曼强度。当木片浸渍TB/PANI时，木材中的木质素可以用TB精确标记，TB的拉曼强度在532 nm激发下增加了三倍。