Grantee Research Project Results
Final Report: Field Test Kits for Rapid Detection of Hazardous Contaminants on Indoor Surfaces
EPA Contract Number: EPD07023Title: Field Test Kits for Rapid Detection of Hazardous Contaminants on Indoor Surfaces
Investigators: Zhou, Xichun
Small Business: ADA Technologies Inc.
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2007 through October 10, 2007
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2007) RFA Text | Recipients Lists
Research Category: SBIR - Homeland Security , Small Business Innovation Research (SBIR)
Description:
Many pathogens and biotoxins can be produced and handled using relatively common chemical and biological equipment. This has led certain deadly biological agents, such as anthrax and ricin, to become favored bioterrorism weapons of rogue countries and terrorist groups worldwide. The threat posed by these materials has created a need for rapid, easy-to-use detection kits that can provide first responders, border guards, and Homeland Security personnel with a means to determine the extent and severity of a perceived or actual biohazard exposure.
Current methods for the detection and identification of microorganisms and viruses and/or their products (e.g., biotoxins) lack the speed, sensitivity, and specificity to be of value in the field as a first responder tool. Although some antibody immunoassay-based test kits have shown promise for quickly reporting the presence of infectious microorganisms and biotoxins, a major limitation of these kits is poor specificity leading to false positive responses. Therefore, there is demand for improved technology to identify hazardous biological and chemical contaminants on indoor surfaces with improved specificity (i.e., very low rates of false positive and false negative responses).
The overall goal of this project is to develop and commercialize a low-cost, easy-to-use test kit for the detection of specific pathogens and biotoxins. In Phase I, ADA Technologies, Inc. (ADA) developed and evaluated test strips based on binding-induced fluorescent resonance energy transfer (FRET) immunoassays for the detection of Bacillus globigii (surrogate for anthrax spores), ricin, and Shiga toxin.
Summary/Accomplishments (Outputs/Outcomes):
In Phase I proof-of-concept testing, ADA developed and evaluated test strips based on binding-induced FRET immunoassays for the detection of simulants of biological toxins and pathogens. Test strips for ricin provided the best performance, with quantifiable fluorescence and little interference from a similar analyte. The results indicate better suitability for detection of protein-size biomolecule toxins such as ricin as opposed to pathogens such as Bacillus globigii. It is speculated that this is due to the short assay time and relative size of the targets—the smaller biomolecules can bind more specifically and tightly with the aptamer. Specific project results with respect to the proposed objectives are listed in Table 1.
Table 1. Objectives from the Phase I Proposal and Project Results
Stated Phase I Objective |
Phase I Result |
Synthesis of specific DNA aptamers against biological hazards |
Aptamer sequences for Bacillus globigii spores (anthrax), ricin, and Shiga-like toxins were identified and custom synthesized with appropriate modification at terminus for conjugation to quantum dots and construction of test strip. |
Design and determination of the test strip configuration with attention to usability, interpretation, sensitivity, and selectivity |
Substrate materials from several vendors were tested for coating adhesion, permeation rate, and strength. The Fusion 5 membrane from Whatman Inc., was selected for the Phase I test strips. |
Design of the approach for generating a control signal on the test strip to indicate proper operation of test strip |
An 18-mer poly(dT) and poly(dA) pair was found to be good for generating control signal on test strip, which can indicate proper operation. |
Verification of performance of test strips to target hazardous contaminants, interferents, and potential cross-reactive compounds |
Sampling buffer solution and assay time were optimized. Test strip for detection of ricin was fully investigated. |
Develop and evaluate swabbing sample collection |
Preliminary sample collection of ricin toxin on metal and plastic surfaces was evaluated. |
Conclusions:
Based on the technical results, ADA believes the best target analytes for this technology are ricin, protein allergens, and molecular biotoxins. Further, ADA’s assessment of the various potential markets, assisted by a Technology Niche Analysis by Foresight Science & Technology, indicates that the best early niche markets for the proposed test kit are food safety and environmental toxin detection (see Table 2). Specifically, Homeland Security applications are not expected to provide the best entry markets for the new aptamer-based technology. As user familiarity and comfort with the technology grows, ADA will expand the range of analytes to address multiple market segments with the same core technology.
Table 2. Alternative Applications for ADA’s Aptamer-Based Test Kit
Applications |
Basis for Feasibility |
Agricultural import |
The analytes are complex molecular shapes suited to high Test frequency modest. |
Supplemental Keywords:
small business, SBIR, EPA, hazardous contaminants, indoor surface contaminants, toxin detection, pollutant monitoring, fluorescent resonance energy transfer detection, FRET, homeland security, treatment/control, sustainable industry/business, scientific discipline, RFA, technology for sustainable environment, sustainable environment, technology, environmental engineering, environmental chemistry, environmental monitoring, hot gas clean up, biotechnology, environmental technology, biowarfare defense, toxin detection, homeland security, aptamer, anthrax, ricin, biotoxin, allergen, detection,, RFA, Scientific Discipline, TREATMENT/CONTROL, Sustainable Industry/Business, Sustainable Environment, Environmental Chemistry, Technology, Technology for Sustainable Environment, Environmental Monitoring, Environmental Engineering, environmental technology, homeland security, biowarfare defense, hot gas clean up, bioterrorism, biotechnology, indoor surfacesThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.