Single domain antibody-quantum dot conjugates for ricin detection by both fluoroimmunoassay and surface plasmon resonance
Single domain antibody-quantum dot conjugates for ricin detection by both fluoroimmunoassay and surface plasmon resonance
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DOI：
10.1016/j.aca.2013.05.010
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发表时间：
2013-07-05
影响因子：
6.2
通讯作者：
Goldman, Ellen R.
中科院分区：
文献类型：
--
作者：
Anderson, George P.;Glaven, Richard H.;Goldman, Ellen R.
稳定的生物识别元件和稳健量子点（QD）的组合有可能为生物销售产生高效的记者。羊角拉和衍生的单域抗体（SDAB）提供了小的热稳定识别元件，可以使用标准DNA方法轻松操纵。 SDAB是在我们实验室通过蛋白质的多组氨酸尾巴制成的二氢丙酸（DHLA）配体cDSE-ZNS核壳QD上自组装的，该蛋白质的蛋白质尾巴与QD表面上的锌离子协调。然后将SDAB-QD生物轭物应用于荧光和表面等离子体共振（SPR）免疫测定中，以检测Ricin，Ricin是一种潜在的生物治疗剂。 SDAB-QD共轭物在氟免疫测定中起作用，用于检测利辛蛋白，与带有常规荧光团标记的相同抗癌蛋白SDAB相比，可提供等效的检测极限。此外，DHLA-QD-SDAB共轭物是SPR三明治测定中非常有效的记者元素，可提供更敏感的检测，而SDAB记者的信号增强相似，而在全尺寸的抗体记者上的信号增强和2-4倍。商业制备的链霉亲和素修饰的聚合物涂覆的QD还放大了SPR信号，当应用于生物素化的抗癌蛋白SDAB与靶向靶向的位置时检测Ricin。但是，当使用这种格式的DHLA-QD-SDAB偶联物时，我们观察到了4倍更大的扩增。 （c）2013年由Elsevier B.V.出版
The combination of stable biorecognition elements and robust quantum dots (QDs) has the potential to yield highly effective reporters for bioanalyses. Llama-derived single domain antibodies (sdAb) provide small thermostable recognition elements that can be easily manipulated using standard DNA methods. The sdAb was self-assembled on dihydrolipoic acid (DHLA) ligand-capped CdSe-ZnS core-shell QDs made in our laboratory through the polyhistidine tail of the protein, which coordinated to zinc ions on the QD surface. The sdAb-QD bioconjugates were then applied in both fluorometric and surface plasmon resonance (SPR) immunoassays for the detection of ricin, a potential biothreat agent. The sdAb-QD conjugates functioned in fluoroimmunoassays for the detection of ricin, providing equivalent limits of detection when compared to the same anti-ricin sdAb labeled with a conventional fluorophore. In addition, the DHLA-QD-sdAb conjugates were very effective reporter elements in SPR sandwich assays, providing more sensitive detection with a signal enhancement of similar to 10-fold over sdAb reporters and 2-4 fold over full sized antibody reporters. Commercially prepared streptavidin-modified polymer-coated QDs also amplified the SPR signal for the detection of ricin when applied to locations where biotinylated anti-ricin sdAb was bound to target; however, we observed a 4-fold greater amplification when using the DHLA-QD-sdAb conjugates in this format. (C) 2013 Published by Elsevier B.V.