Grantee Research Project Results
Final Report: Nanosensor for Detection of Saxitoxin
EPA Grant Number: GR832382Title: Nanosensor for Detection of Saxitoxin
Investigators: Gawley, Robert E.
Institution: University of Arkansas
EPA Project Officer: Hahn, Intaek
Project Period: August 1, 2005 through July 31, 2008
Project Amount: $340,000
RFA: Greater Research Opportunities: Research in Nanoscale Science Engineering and Technology (2004) RFA Text | Recipients Lists
Research Category: Nanotechnology , Safer Chemicals
Objective:
The objective of this research project is to: design and prepare nanoscale sensors for the detection of saxitoxin and other paralalytic shellfish toxins (PSTs).
Approach:
We will base our work on the principles of molecular recognition and photoinduced electron transfer, and the techniques of chemical synthesis, from the molecular to macromolecular scale. We have previously developed a small molecule chemosensor that is selective for saxitoxin over several organic analytes and three common cations found in environmental samples. Using this work as a foundation, we will develop a new generation of fluorescent sensor moieties that are selective for saxitoxin and avoid interference by constituents of the shellfish matrix or other environmental constituents. The sensor moiety will then be incorporated into a nanometer-sized dendrimer to improve sensitivity. To evaluate selectivity, we will screen our sensors against shellfish extracts that have been found to be both toxic and nontoxic by mouse bioassay, and certify the results using HPLC analysis. Finally, we will attach the dendritic sensors to solid support to conduct a preliminary evaluation of a visual sensor.
Summary/Accomplishments (Outputs/Outcomes):
For the past several years, we have been investigating a class of crown ethers having a pendant fluorophore for the detection of saxitoxin (Figure 1).1-3 We have investigated several aromatic groups for the fluorescence response, including the anthracene,1,2 coumarin,3 and acridine4 fluorophores shown in Figure 1. The binding constants for these compounds to saxitoxin is in the range of 104 – 105 M–1.Expected Results:
The research described herein will lead to a photochemical method that could provide a practical alternative to mouse bioassay for the detection of the pathogen saxitoxin in environmental samples. At present, detection of saxitoxin and its congeners in seafood is done by mouse bioassay. Chemical means of detection such as liquid chromatography/mass spectrometry (LC/MS) require considerable technical skill and expensive equipment. Such techniques are not amenable to high-throughput or remote analysis. We anticipate that this project will afford nanoscale sensors that could be attached to a solid support for detection of saxitoxin.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
Other project views: | All 3 publications | 3 publications in selected types | All 3 journal articles |
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Kele P, Orbulescu J, Gawley RE, Leblanc RM. Spectroscopic detection of saxitoxin:an alternative to mouse bioassay. Chemical Communications 2006;(14):1494-1496. |
GR832382 (2006) GR832382 (Final) |
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Lewis P, Fritsch I, Gawley RE, Henry R, Knight A, Lay Jr. JO, Liyanage R, McLachlin J. Dynamics of saxitoxin binding to saxiphilin c-lobe reveals conformational change. Toxicon 2008;51(2):208-217. |
GR832382 (Final) |
Exit Exit |
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Mao H, Thorne JB, Pharr JS, Gawley RE. Effect of crown ether ring size on binding and fluorescence response to saxitoxin in anthracylmethyl monoazacrown ether chemosensors. Canadian Journal of Chemistry 2006;84(10):1273-1279. |
GR832382 (2006) GR832382 (Final) R829599 (Final) |
Exit |
Supplemental Keywords:
, RFA, Scientific Discipline, Water, TREATMENT/CONTROL, Ecosystem Protection/Environmental Exposure & Risk, Sustainable Industry/Business, Sustainable Environment, Environmental Chemistry, Technology, Technology for Sustainable Environment, Monitoring/Modeling, Environmental Monitoring, New/Innovative technologies, Environmental Engineering, Engineering, Chemistry, & Physics, aquatic ecosystem, nanosensors, chemical sensors, nanotechnology, environmental sustainability, saxitoxin detection, chemical composition, aquatic toxins, environmentally applicable nanoparticles, analytical chemistry, nanoscale sensors, nano engineering, innovative technologies, nanoengineering, marine toxinsProgress and Final Reports:
Original AbstractThe 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.