School of Electrical Engineering and Computer Science, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
Ottawa-Carleton Institute for Biomedical Engineering, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Nov 5;280:121533. doi: 10.1016/j.saa.2022.121533. Epub 2022 Jun 20.
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.
过去几十年中，新发和再现的细菌性传染病的爆发有所增加，因此需要快速检测和治疗。表面增强拉曼光谱（SERS）是一种可用于开发生物样本中细菌快速筛选系统的技术。优化纳米颗粒合成中的封端剂非常重要，因为封端剂负责控制纳米颗粒的形态特征和化学性质，这对于 SERS 是必不可少的。据我们所知，本文首次研究了用巯基葡萄糖和聚乙烯吡咯烷酮（PVP）封端的金纳米颗粒在 SERS 检测细菌中的应用，作为替代常用于 SERS 检测细菌的柠檬酸封端金纳米颗粒的方法。本研究使用了三种不同的细菌：痤疮丙酸杆菌、大肠杆菌和金黄色葡萄球菌（甲氧西林敏感和耐甲氧西林）。本研究表明，巯基葡萄糖和柠檬酸都对细菌种类的鉴定有很好的贡献，而巯基葡萄糖在两种类型的金黄色葡萄球菌鉴定中三种封端剂中的表现最好。此外，尽管 PVP 在每种类型的细菌的 SERS 光谱中都显示出较高的拉曼峰，但由于其在产生来自细菌细胞中不同核酸成分的响应方面效果较低，因此在鉴定菌种和菌株方面的贡献最小。
