Characterization of the Surface Enhanced Raman Scattering (SERS) of bacteria
Characterization of the Surface Enhanced Raman Scattering (SERS) of bacteria
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DOI：
10.1021/jp040442n
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发表时间：
2005-01-13
影响因子：
3.3
通讯作者：
Ziegler, LD
中科院分区：
文献类型：
--
作者：
Premasiri, WR;Moir, DT;Ziegler, LD
报道了在785 nm激发下，在覆盖SiO2的新型金纳米颗粒（约80 nm）上获得的多种细菌的表面增强拉曼散射（SERS）。在这些SERS活性底物上，革兰氏阳性和革兰氏阴性细菌的每个细菌的拉曼截面都增强了bbb10(4)。在该激发波长下，细菌的SERS光谱比其相应的非SERS（体）拉曼光谱更少拥挤，表现出更大的物种分化。在芽孢杆菌种类的体拉曼发射中观察到的荧光在相应的SERS光谱中不明显。尽管纳米结构的金属表面产生了场增强效应，但由于能量转移过程，这种荧光成分似乎“淬灭”，这并不会减少拉曼发射。表面增强效应允许在低入射功率和短数据采集时间下观察单个细菌细胞的拉曼光谱。炭疽杆菌的SERS光谱说明了这种单细胞水平的能力。与以往的SERS研究比较揭示了SERS振动特征如何强烈依赖于SERS活性底物的形态和性质。这些结果证明了SERS在这些金颗粒覆盖的玻璃底物上具有物种和菌株特异性的细菌病原体检测和鉴定的潜力。
The surface enhanced Raman scattering (SERS) of a number of species and strains of bacteria obtained on novel gold nanoparticle (similar to80 nm) covered SiO2 substrates excited at 785 nm is reported. Raman cross-section enhancements of >10(4) per bacterium are found for both Gram-positive and Gram-negative bacteria on these SERS active substrates. The SERS spectra of bacteria are spectrally less congested and exhibit greater species differentiation than their corresponding non-SERS (bulk) Raman spectra at this excitation wavelength. Fluorescence observed in the bulk Raman emission of Bacillus species is not apparent in the corresponding SERS spectra. Despite the field enhancement effects arising from the nanostructured metal surface, this fluorescence component appears "quenched" due to an energy transfer process which does not diminish the Raman emission. The surface enhancement effect allows the observation of Raman spectra of single bacterial cells excited at low incident powers and short data acquisition times. SERS spectra of B. anthracis Sterne illustrate this single cell level capability. Comparison with previous SERS studies reveals how the SERS vibrational signatures are strongly dependent on the morphology and nature of the SERS active substrates. The potential of SERS for detection and identification of bacterial pathogens with species and strain specificity on these gold particle covered glassy substrates is demonstrated by these results.