One of the goals of this project is to develop new sensors to detect agricultural chemicals in surface and ground water. Current monitoring methods are expensive and require sample removal, which can disturb the composition. Although EDB is not widely used in Colorado, it was recently the cause of a 3-year water supply problem in Woodland Park. Furthermore, it is widely used in other states and was the fourth most often detected pesticide in drinking water wells nationwide in 1992. The biosensor design utilizes an enzyme from the bacterium Rhodococcus sp.
Similar enzymes exist for other chlorinated pesticides.
This detection limit is 1000-fold lower than our 1996 level. The biosensor responded to 1,2-dichloroethane but had high selectivity for EDB against TCE, PCE, and acetate. The pH and buffer capacity dependence of the biosensor were characterized. No other device for inexpensive, continuous, compound-specific sensing has been developed. Sensors of this type would be useful for monitoring water supplies, especially if sensors for different compounds were bundled together.