Ultra-fast pg/ml anthrax toxin (protective antigen) detection assay based on microwave-accelerated metal-enhanced fluorescence
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Author/Creator ORCID
Date
2012-06-01
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Citation of Original Publication
Dragan, Anatoliy I., Mark T. Albrecht, Radmila Pavlovic, Andrea M. Keane-Myers, and Chris D. Geddes. “Ultra-Fast Pg/Ml Anthrax Toxin (Protective Antigen) Detection Assay Based on Microwave-Accelerated Metal-Enhanced Fluorescence.” Analytical Biochemistry 425, no. 1 (June 1, 2012): 54–61. https://doi.org/10.1016/j.ab.2012.02.040.
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This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
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Public Domain
Abstract
Rapid presymptomatic diagnosis of Bacillus anthracis at early stages of infection plays a crucial role in prompt medical intervention to prevent rapid disease progression and accumulation of lethal levels of toxin. To detect low levels of the anthrax protective antigen (PA) exotoxin in biological fluids, we have developed a metal-enhanced fluorescence (MEF)–PA assay using a combination of the MEF effect and microwave-accelerated PA protein surface absorption. The assay is based on a modified version of our “rapid catch and signal” (RCS) technology previously designed for the ultra-fast and sensitive analysis of genomic DNA sequences. Technologically, the proposed MEF–PA assay uses standard 96-well plastic plates modified with silver island films (SiFs) grown within the wells. It is shown that the fluorescent probe, covalently attached to the secondary antibody, plays a crucial role of indicating complex formation (i.e., shows a strong MEF response to the recognition event). Microwave irradiation rapidly accelerates PA deposition onto the surface (“rapid catch”), significantly speeding up the MEF–PA assay and resulting in a total assay run time of less than 40min with an analytical sensitivity of less than 1pg/ml PA.