Environmental contaminants like fluoride, lead, and pesticides are often found in or run off into groundwater. Researchers have simple ways to measure the concentrations of these contaminants in lab environments, but the same cannot be said for measuring the concentration of contaminants in the environment.

These procedures often require costly specialized lab equipment. Recent efforts in synthetic biology have leveraged the functionality of cell biosensors to both detect and report environmental contaminants in a cost-effective and scalable  manner.

During the development of these technologies, scientists have struggled to answer the question of protecting sensor components from substances that naturally exist in extracted samples. A cross-disciplinary team of synthetic biologists at Northwestern University is developing a sensor platform that will be able to detect a range of environmental and biological targets in real-world samples and survive degradation from contaminants, according to technology.org.

Using an established riboswitch to build a sensor for fluoride, the team found they could protect the sensor by encapsulating the sensor inside a fatty membrane, similarly to how cells protect their organelles. A riboswitch is a synthetic biological component that includes a fluorescent RNA or protein that lights up in response to contaminants.

Cell-free synthetic biology, in which engineered biomolecular systems are used to activate biological machinery rather than living cells, is compelling because it is efficient, versatile, and low-cost. Other uses for this technology could be to develop sensors that can flow through the human body to detect small molecules and biomarkers before the sensor is retrieved through urine or another passive method. It could also detect levels of nitrate in soil and aid in monitoring.

In a new paper published in Science Advances, researchers demonstrated that they could tune and control their sensor performance by modifying the makeup of the lipid bilayer membrane.

Groundwater hydrology (GEO-210) is a geology course taught by Professor Mason Stahl. The course partially examines the role of geology in determining groundwater chemistry and quality, as well as the connections between groundwater and human health and the importance of groundwater in the global food supply.