Nanosensor for Detection of SaxitoxinEPA Grant Number: GR832382
Title: Nanosensor for Detection of Saxitoxin
Investigators: Gawley, Robert E.
Institution: University of Arkansas - Fayetteville
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
This proposal seeks funding to develop a fluorescent nanosensor for saxitoxin, a common seafood poison that is also on the Government’s list of select agents, and is of concern because of its potential as a point-source poison.
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.
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.