Chu Hsiaoyun, Huang Yaowen, Zhao Yiping
Department of Food Science and Technology, The University of Georgia, Athens, Georgia 30602, USA.
Appl Spectrosc. 2008 Aug;62(8):922-31. doi: 10.1366/000370208785284330.
Surface-enhanced Raman scattering (SERS) using novel silver nanorod array substrates has been used for the detection of pathogenic bacteria. The substrate consists of a base layer of 500 nm silver film on a glass slide and a layer of silver nanorod array with a length of approximately 1 microm produced by the oblique angle deposition method at a vapor incident angle of 86 degrees . Spectra from whole cell bacteria, Generic Escherichia coli, E. coli O157:H7, E. coli DH 5alpha, Staphylococcus aureus, S. epidermidis, and Salmonella typhimurium, and bacteria mixtures have been obtained. This SERS active substrate can detect spectral differences between Gram types, different species, their mixture, and strains. Principal component analysis (PCA) has been applied to classify the spectra. Viable and nonviable cells have also been examined, and significantly reduced SERS responses were observed for nonviable cells. SERS detection of bacteria at the single cell level, excited at low incident laser power (12 micro W) and short collection time (10 s), has also been demonstrated. These results indicate that the SERS-active silver nanorod array substrate is a potential analytical sensor for rapid identification of microorganisms with a minimum of sample preparation.
使用新型银纳米棒阵列基底的表面增强拉曼散射（SERS）已用于病原菌的检测。该基底由载玻片上500 nm银膜的底层和通过在86度的气相入射角下采用斜角沉积法制备的长度约为1微米的银纳米棒阵列层组成。已获得全细胞细菌、普通大肠杆菌、大肠杆菌O157:H7、大肠杆菌DH 5α、金黄色葡萄球菌、表皮葡萄球菌、鼠伤寒沙门氏菌以及细菌混合物的光谱。这种SERS活性基底能够检测革兰氏类型、不同物种、它们的混合物以及菌株之间的光谱差异。主成分分析（PCA）已应用于光谱分类。还对活细胞和死细胞进行了检测，观察到死细胞的SERS响应显著降低。在低入射激光功率（12 μW）和短采集时间（10 s）激发下，也已证明在单细胞水平上对细菌的SERS检测。这些结果表明，SERS活性银纳米棒阵列基底是一种潜在的分析传感器，可用于在最少样品制备的情况下快速鉴定微生物。
