Liu Wen, Wei Linbo, Wang Dongmei, Zhu Chengye, Huang Yuting, Gong Zhengjun, Tang Changyu, Fan Meikun
Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China.
Chengdu Development Center of Science and Technology, China Academy of Engineering Physics, Chengdu 610200, China.
Anal Chem. 2022 May 10;94(18):6791-6798. doi: 10.1021/acs.analchem.2c00502. Epub 2022 Apr 27.
Surface-enhanced Raman spectroscopy (SERS) stands out in the field of microbial analysis due to its rich molecular information, fast analysis speed, and high sensitivity. However, achieving strain-level differentiation is still challenging because numerous bacterial species inevitably have very similar SERS profiles. Here, a method inspired by the black-box theory was proposed to boost the spectral differences, where the undifferentiated bacteria was considered as a type of black-box, external environmental stress was used as the input, and the SERS spectra of bacteria exposed to the same stress was output. For proof of the concept, three types of environmental stress were explored, i.e., ethanol, ultraviolet light (UV), and ultrasound. () and three types of () were all subjected to the stimuli (stress) before SERS measurement. Then the collected spectra were processed only by simple principal component analysis (PCA) to achieve differentiation. The results showed that appropriate stress was beneficial to increase the differences in bacterial SERS spectra. When sonication at 490 W for 60 s was used as the input, the optimal differentiation of bacteria at the species ( and ) and strain-level (three ) can be achieved.
表面增强拉曼光谱（SERS）因其丰富的分子信息、快速的分析速度和高灵敏度而在微生物分析领域脱颖而出。然而，实现菌株水平的区分仍然具有挑战性，因为许多细菌种类不可避免地具有非常相似的SERS谱图。在此，提出了一种受黑箱理论启发的方法来增强光谱差异，即将未分化的细菌视为一种黑箱，将外部环境压力作为输入，并输出暴露于相同压力下的细菌的SERS光谱。为了验证这一概念，探索了三种环境压力，即乙醇、紫外线（UV）和超声波。（）和三种类型的（）在进行SERS测量之前均受到刺激（压力）。然后仅通过简单的主成分分析（PCA）对收集到的光谱进行处理以实现区分。结果表明，适当的压力有利于增加细菌SERS光谱的差异。当以490 W超声处理60 s作为输入时，可以实现细菌在物种（和）和菌株水平（三种）上的最佳区分。
