Environmental researchers are developing new biosensors for testing water

As a consequence of demographic change, the consumption of medicines is increasing in industrial nations. Large amounts of pharmaceutical agents are already deposited at waste treatment facilities through waste water. As these substances usually cannot be removed effectively, surface water organisms are subjected to a cocktail of drugs. Just a few micrograms per liter are enough to cause harmful side effects in fish.

In the joint project "EffPharm" biologists, biochemists and analytical chemists are working to find a solution to the problem. The project is funded by the German Environment Agency (UBA) and coordinated by ecotoxicologist Professor Rita Triebskorn. The working group headed by Dr. Manfred Frey from the Steinbeis Innovation Center for Cell Culture Technology at the Mannheim University of Applied Sciences has succeeded in developing cell-based biosensors for two classes of drugs. These biosensors can detect the binding of such substances to their target molecules (receptors) in treated waste water in real time. At the University of Tübingen, Professor Rita Triebskorn and Professor Heinz Köhler from the Animal Physiological Ecology working group have demonstrated how sensitive these biosensors are. They were able to detect very low concentrations of the drugs at levels which are harmful to water organisms. Dr. Marco Scheurer from the Water Technology Center in Karlsruhe showed that the new biosensors capture a large proportion of the compounds that had previously been detected by complex and time-intensive chemical analysis.

The newly developed biosensors have many more advantages in contrast to previous approaches. After the biosensor cell lines are exposed to drugs in water samples, a fluorescence signal appears within seconds. In contrast to conventional sensors, the biosensors detect the effect of chemicals in the cell in real-time and avoids misleading information which may occur in sensors that take several hours to generate a signal. Thanks to their mechanism of action, the biosensors can detect future beta-blockers or NSAIDS without knowing their exact chemical structure.

"It would be desirable for the technology developed here to be used in monitoring programs to determine the water quality and the cleaning performance of sewage treatment plants," says Professor Rita Triebskorn. "This would close an important gap in the plausibility chain between the detection of pharmaceutical substances in water and the health effects of the organisms concerned."