A Chemically Synthesized Capture Agent Enables the Selective, Sensitive, and Robust Electrochemical Detection of Anthrax Protective Antigen

다국어 초록 (Multilingual Abstract)

<P>We report on a robust and sensitive approach for detecting protective antigen (PA) exotoxin from <I>Bacillus anthracis</I> in complex media. A peptide-based capture agent against PA was developed by improving a bacteria display-developed peptide into a highly selective biligand through <I>in situ</I> click screening against a large, chemically synthesized peptide library. This biligand was coupled with an electrochemical enzyme-linked immunosorbent assay utilizing nanostructured gold electrodes. The resultant assay yielded a limit of detection of PA of 170 pg/mL (2.1 pM) in buffer, with minimal sensitivity reduction in 1% serum. The powdered capture agent could be stably stored for several days at 65 °C, and the full electrochemical biosensor showed no loss of performance after extended storage at 40 °C. The engineered stability and specificity of this assay should be extendable to other cases in which biomolecular detection in demanding environments is required.</P><P><B>Graphic Abstract</B>
<IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2013/ancac3.2013.7.issue-10/nn404296k/production/images/medium/nn-2013-04296k_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn404296k'>ACS Electronic Supporting Info</A></P>