水介质中大肠杆菌的可变光程长度傅里叶变换红外光谱
Variable-Path-Length FTIR of E. coli in Aqueous Media
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中文总结 AI 辅助
本研究采用中红外光纤探针结合可变光程长度FTIR显微光谱技术，实现水介质中大肠杆菌不同深度信号的解析，解决了传统透射红外光谱光程固定或过大的应用局限。
中文摘要 AI 辅助
透射红外光谱已广泛用于水介质中生物样品的化学分析，但其应用范围受限于光程长度，光程要么过大要么固定，给分析高吸收或异质性样品带来挑战。本研究采用中红外（mid-IR）光纤探针进行水介质中大肠杆菌（E. coli）样品的傅里叶变换红外（FTIR）显微光谱分析，可连续调节光程长度并采集近表面和本体区域的信号。1548 cm-1处蛋白质信号的中红外吸光度随光程长度线性增加，符合比尔-朗伯定律。利用光程依赖光谱计算水介质中大肠杆菌悬浮液的空间异质性吸收系数，结果表明该光纤技术能够解析生物溶液不同深度的信号。
英文摘要
Transmission infrared spectroscopy has been widely used for chemical analysis of biological samples in aqueous environments. However, its scope of applications has been limited by the path length, which is either too large or fixed, posing challenges for analyzing highly absorbing or heterogeneous samples. In this work, a mid-infrared (mid-IR) optical fiber probe was used for Fourier transform infrared (FTIR) micro-spectroscopy of aqueous Escherichia coli (E. coli) samples, providing continuous tuning of optical path length and sampling of near-surface and bulk regions. The mid-IR absorbance of the protein signal at 1548 cm-1 increased linearly with path length, consistent with the Beer-Lambert law. Path-length dependent spectra were used to calculate the spatially heterogeneous absorption coefficient of E. coli suspensions in aqueous media. The results demonstrate the ability of our fiber-based technique to resolve signals originating from different depths into the biological solution.
