Detection of single bacterial pathogens with semiconductor quantum dots
Detection of single bacterial pathogens with semiconductor quantum dots
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DOI：
10.1021/ac050641i
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发表时间：
2005-08-01
影响因子：
7.4
通讯作者：
Krauss, TD
中科院分区：
文献类型：
--
作者：
Hahn, MA;Tabb, JS;Krauss, TD
应用半导体量子点（QDs）技术对致病性大肠杆菌O157:H7血清型进行单细胞荧光检测。该系统由CdSe/ZnS核/壳量子点与链霉亲和素偶联组成，比使用普通有机染料的类似检测方法灵敏度高2个数量级。该致病菌菌株比普通实验室菌株（大肠杆菌DH5 α）具有选择性，这是通过使用特异性生物素化抗体获得的，也证明了QD标记。在连续激发下，这些量子点可保持数小时的高荧光强度，而典型的有机染料在几秒钟内就会褪色，从而可以在单细胞荧光检测中更快速、更准确地鉴定大肠杆菌O157:H7。这种基于抗体-抗原和链亲和素-生物素相互作用的间接QD标记方法具有足够的灵活性，可以扩展到其他系统，并且在同时多色检测方案中具有很大的潜力。
Semiconductor quantum dots (QDs) have been used in a simple fluorometric assay to detect single cells of the pathogenic Escherichia coli O157:H7 serotype. Composed of CdSe/ZnS core/shell QDs conjugated to streptavidin, this system exhibits 2 orders of magnitude more sensitivity than a similar assay using a common organic dye. Selectivity for this pathogenic bacterial strain over a common lab strain (E. coli DH5 alpha), which is gained from the use of specific biotinylated antibodies, is also demonstrated for QD labeling. Under continuous excitation, these QDs retain high fluorescence intensities for hours, whereas a typical organic dye bleaches within seconds, allowing for more rapid and accurate identification of E. coli O157:H7 in single-cell fluorescence-based assays. This indirect QD labeling method, based on antibody-antigen and streptavidin-biotin interactions, is flexible enough to expand to other systems and has great potential for use in simultaneous multicolor detection schemes.