Rivera-Betancourt Omar E, Sheppard Edward S, Krause Duncan C, Dluhy Richard A
Department of Chemistry, University of Georgia, Athens, GA 30602, USA.
Analyst. 2014 Sep 7;139(17):4287-95. doi: 10.1039/c4an00596a. Epub 2014 Jul 14.
Mycoplasma pneumoniae is a major cause of respiratory disease in humans and accounts for as much as 20% of all community-acquired pneumonia. Existing mycoplasma diagnosis is primarily limited by the poor success rate at culturing the bacteria from clinical samples. There is a critical need to develop a new platform for mycoplasma detection that has high sensitivity, specificity, and expediency. Here we report the layer-by-layer (LBL) encapsulation of M. pneumoniae cells with Ag nanoparticles in a matrix of the polyelectrolytes poly(allylamine hydrochloride) (PAH) and poly(styrene sulfonate) (PSS). We evaluated nanoparticle encapsulated mycoplasma cells as a platform for the differentiation of M. pneumoniae strains using surface enhanced Raman scattering (SERS) combined with multivariate statistical analysis. Three separate M. pneumoniae strains (M129, FH and II-3) were studied. Scanning electron microscopy and fluorescence imaging showed that the Ag nanoparticles were incorporated between the oppositely charged polyelectrolyte layers. SERS spectra showed that LBL encapsulation provides excellent spectral reproducibility. Multivariate statistical analysis of the Raman spectra differentiated the three M. pneumoniae strains with 97-100% specificity and sensitivity, and low (0.1-0.4) root mean square error. These results indicated that nanoparticle and polyelectrolyte encapsulation of M. pneumoniae is a potentially powerful platform for rapid and sensitive SERS-based bacterial identification.
肺炎支原体是人类呼吸道疾病的主要病因，占所有社区获得性肺炎的20%之多。现有的支原体诊断主要受限于从临床样本中培养该细菌的成功率较低。迫切需要开发一种新的支原体检测平台，该平台具有高灵敏度、高特异性和便捷性。在此，我们报告了在聚电解质聚（烯丙胺盐酸盐）（PAH）和聚（苯乙烯磺酸盐）（PSS）的基质中，用银纳米颗粒对肺炎支原体细胞进行逐层（LBL）封装。我们评估了纳米颗粒封装的支原体细胞作为利用表面增强拉曼散射（SERS）结合多变量统计分析来区分肺炎支原体菌株的平台。研究了三种不同的肺炎支原体菌株（M129、FH和II - 3）。扫描电子显微镜和荧光成像表明，银纳米颗粒掺入了带相反电荷的聚电解质层之间。SERS光谱表明，LBL封装提供了出色的光谱重现性。对拉曼光谱的多变量统计分析以97 - 100%的特异性和灵敏度以及低（0.1 - 0.4）的均方根误差区分了三种肺炎支原体菌株。这些结果表明，肺炎支原体的纳米颗粒和聚电解质封装是基于SERS的快速灵敏细菌鉴定的潜在强大平台。
