Antibody-Based Biosensor Aids Environmental Cleanups

(U.S. Coast Guard)

Researchers at the Virginia Institute of Marine Science (VIMS) in Gloucester Point have built and tested an aquatic sensor device that uses antibodies to detect marine pollutants. The developers of the device published their test results that appear today in the journal Environmental Toxicology and Chemistry (paid subscription required).

The research team that built the sensor, which is small and sturdy enough to be used from a boat, say it can detect pollutants like oil much faster and less expensively than current technologies. Tests of the device in the Elizabeth River and Yorktown Creek that drain into lower Chesapeake Bay, suggest that the instrument can process samples in less than 10 minutes, detect pollutants at levels as low as just a few parts per billion, and do so at a cost of just pennies per sample. Current technology requires hours of lab work, with a per-sample cost of up to $1,000.

The technology behind the biosensor combines monoclonal antibodies with electronic sensors. Antibodies are proteins produced by the immune system of humans and other mammals, which recognize and bind with large organic molecules such as proteins or with viruses. The VIMS team then linked proteins to aquatic contaminants, and exposed mice to these paired protein/contaminant compounds in a manner very similar to a vaccination against disease.

The mice’s lymphatic systems then produced antibodies to the pollutants. From these antibodies, the VIMS team produced monoclonal antibodies in large enough quantities for the biosensor. A monoclonal antibody is an engineered, laboratory-produced molecule that binds to a target — in this case the specific pollutant in the water — which enables the sensor to identify it. The VIMS researchers worked with Sapidyne Instruments Inc. in Boise, Idaho to adapt a spectroscopic assay to recognize when an antibody binds with a contaminant and translate that recognition into an electrical signal.

The tests in the Elizabeth River took place during clean up of a site contaminated by polycyclic aromatic hydrocarbons (PAHs), byproducts of decades of industrial use of creosote to treat marine pilings. The Environmental Protection Agency considers PAHs highly toxic, which can cause red blood cell damage, leading to anemia, or a suppressed immune system. PAHs were also among the pollutants found in the Gulf of Mexico after the BP oil spill last year.

The biosensor allowed the researchers to quantify PAH concentrations while the Elizabeth River clean up was taking place, gaining knowledge about water quality surrounding the remediation site. VIMS doctoral candidate and lead author Candace Spier says the test was “the first use of an antibody-based biosensor to guide sampling efforts through near real-time evaluation of environmental contamination.”

In the Yorktown Creek study, the researchers used the biosensor to track the runoff of PAHs from roadways and soils during a rainstorm. Comparison of the biosensor’s field readings with later readings from a mass spectrometer at VIMS showed that the biosensor was as accurate as the more expensive and slower lab machines.

Read more: New X Prize Challenge for Ocean Oil Cleanup

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