A team of synthetic biologists has developed a sensor platform that can detect a range of environmental and biological targets in real-world samples.
The platform uses an established riboswitch to build a biosensor for fluoride, which is protected and operates similarly to cells by being encapsulated in a fatty membrane. By modifying the makeup and penetrability of the lipid bilayer membrane, the researchers were able to tune and control the performance of their sensor.
The use of cell-free synthetic biology, in which engineered biomolecular systems are used to activate biological machinery rather than living cells, allows for efficient, versatile and low-cost monitoring of the environment for health and sustainability purposes. The sensor was designed using bacterial cell extracts to power gene expression reactions that produce visual outputs within minutes and at a low cost.
The researchers at Northwestern University were able to overcome the problem of fitting everything inside a small container and scaling it up by using a vesicle, a membrane with two layers, to protect the sensor and allow it to work in samples that may be contaminated with other substances. They also demonstrated that the sensor can be used to detect contaminants in water samples from Chicago’s Lake Michigan and in spiked water samples.
“So much data is being generated, and a lot of it is being driven by health apps like smart watches,” said Julius Lucks, a co-corresponding author and professor of chemical and biological engineering at Northwestern’s McCormick School of Engineering. “We can sense our heartbeat, our temperature, but if you think about it, we really have no way to sense chemical things. We’re living in an information age, but the information we have is so miniscule — chemical sensing opens enormous dimensions of information that you can tap into.”