In this study, a novel strategy based on the combination of 3D SERS and LIBS was developed for qualitative and quantitative detection of bacteria. SERS-active Ag nanoparticles (AgNPs) were prepared by an improved in situ synthesis method, and reproducible SERS spectra of bacteria were obtained by natural evaporation of a droplet of the in situ synthesized sample. Four types of bacteria were classified via principal component analysis (PCA) and hierarchy cluster analysis (HCA). LIBS acted as a quantitative technique for bacterial detection based on the intracellular mineral cations, and bacteria could be detected in a linear range of 5 × 103-5 × 107 CFU mL-1, with recovery values ranging from 81.0% to 101.7%. The whole detection process including sample preparation and detection could be completed in approximately 30 min. With short assay time and simple operation, the proposed strategy has showed great potential for bacterial analysis.

中文翻译：

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一种通过三维表面增强拉曼散射 (3D SERS) 和激光诱导击穿光谱 (LIBS) 相结合的快速检测水中细菌的新策略

在这项研究中，开发了一种基于 3D SERS 和 LIBS 组合的新策略，用于细菌的定性和定量检测。通过改进的原位合成方法制备了 SERS 活性银纳米粒子 (AgNPs)，并通过原位合成样品液滴的自然蒸发获得了可重现的细菌 SERS 光谱。通过主成分分析（PCA）和层次聚类分析（HCA）对四种细菌进行分类。LIBS 作为一种基于细胞内矿物阳离子的细菌检测定量技术，可在 5 × 103-5 × 107 CFU mL-1 的线性范围内检测细菌，回收率范围为 81.0% 至 101.7%。整个检测过程包括样品制备和检测可在大约 30 分钟内完成。