Abstract：
The increase in outbreaks of emerging and re-emerging bacterial infections over the last few decades calls for their rapid detection and treatment. Surface-enhanced Raman spectroscopy (SERS) is a technique that can be applied to develop fast screening systems for bacterial presence in biological samples. Optimizing the capping agents in nanoparticle synthesis is important because capping agents are responsible for controlling the morphological features and chemical properties of the nanoparticles that are essential for SERS. To the best of our knowledge, this paper is the first to study the application of gold nanoparticles capped with thioglucose and polyvinylpyrrolidone (PVP) in SERS detection of bacteria as an alternative to the citrate-capped gold nanoparticles that are often used in SERS detection of bacteria. Three different species of bacteria were used in this study: Cutibacterium acnes, Escherichia coli and Staphylococcus aureus (methicillin-sensitive and methicillin-resistant). This study demonstrates that the thioglucose, citrate both show good contribution in bacterial species identification and the thioglucose shows the best among the three capping agents in two types of S. aureus identification. Moreover, although PVP showed high Raman peaks in the SERS spectrum for each type of bacteria, it showed least contribution in identifying species and strains due to its low efficacy in producing responses from different nucleic acid components in the bacteria cells.
摘要：
在过去的几十年中，新出现和重新出现的细菌感染的爆发增加需要对其进行快速检测和治疗。表面增强拉曼光谱（SERS）是一种可用于开发生物样品中细菌存在的快速筛选系统的技术。在纳米粒子合成中优化封端剂是重要的,因为封端剂负责控制纳米粒子的形态特征和化学性质,这对于SERS是必需的。据我们所知,本文首次研究了硫代葡萄糖和聚乙烯吡咯烷酮（PVP）覆盖的金纳米粒子在细菌SERS检测中的应用，作为经常用于细菌SERS检测的柠檬酸盐覆盖的金纳米粒子的替代方法。在这项研究中使用了三种不同的细菌：粉刺杆菌，大肠杆菌和金黄色葡萄球菌（甲氧西林敏感和耐甲氧西林）。这项研究表明，硫代葡萄糖，柠檬酸盐在细菌物种鉴定中都显示出良好的贡献，并且在两种类型的金黄色葡萄球菌鉴定中，硫代葡萄糖在三种封端剂中显示出最佳。此外，尽管PVP在每种细菌的SERS光谱中显示出高拉曼峰，它在鉴定物种和菌株方面的贡献最小，因为它在从细菌细胞中的不同核酸成分产生反应方面的功效低。
