Synthetic biologists from Northwestern University have invented a low-cost, simple-to-use hand-held gadget that can tell consumers whether their water is suitable to drink in minutes.
The novel gadget performs a variety of logic operations by using efficient and customizable genetic networks that imitate electrical circuits.
The researchers designed cell-free molecules into more of an analog-to-digital converter (ADC), a circuit type used in practically all electronic devices, as one of the DNA-based circuits. The ADC circuit of the water-quality device converts an analog input (contaminants) into a digital response (a visual signal).
The gadget, which is made up of eight microscopic test tubes, flashes green when it finds contamination. The amount of tubes that light is determined by the level of pollution. If just one tube illuminates, the water sample is contaminated to a trace level. However, when all eight tubes light up, the water is highly polluted. To put it another way, the greater the contamination level, the stronger the signal.
The first system was a bio-sensor that worked like a taste bud. Now they’ve added a genetic network that performs like a brain. The bio-sensor detects pollution, but the bio-output is fed to the genetic network, or circuitry, which functions like a brain and performs logic.
The reprogrammed “molecular brains” were freeze-dried and placed in test tubes to make them shelf-stable. By adding a single drop to each tube, a chain of events and interactions is put in motion, resulting in the freeze-dried pellet glowing in the presence of a pollutant.
Lucks and his colleagues proved that the novel method could measure concentration amounts of zinc, an antibiotic, as well as an industrial metabolite.
Lucks and his colleagues anticipate that, in the end, people will be able to check their own water on a frequent basis. That might soon be a reality, thanks to low-cost hand-held devices like ROSALIND.
The research was published in Nature.
