Currently, testing water is a relatively tedious process which involves collecting samples, sending them to a laboratory and waiting for several days for the results to be released. While this is happening, you remain in the dark on whether the water is safe to use, which can be frustrating and also worrying.
The scenario may change in a short while, however. Gustav Skands, co-founder and CEO of SBT Aqua, and
a group of students from the Technical University of Denmark have created a sensor that they claim can instantly detect bacteria in water.
The sensor uses impedance flow cytometry. Simply put, a liquid sample is continuously injected into a microfluidic channel lined with electrodes through which a multi-frequency signal is applied.
As bacteria and water particles move across the electrodes, there is a change in resistance, or impedance. The impedance change for bacteria is different from that of other particles; it is therefore possible to provide a highly accurate estimate of both the bacteria and particle count in the sample. At the same time, all bacteria species in the liquid sample will be detected.
Along with its use in handheld devices that could be used to perform inspections at various locations, the sensor could also be integrated into multiple interconnected unmanned water-testing stations along one waterway. If any detect harmful bacteria, they could instantly raise an alarm while tracking the flow of the contamination. Water can be monitored 24/7, considerably reducing manpower and time.
Another significant advantage is that this solution does away with the potentially dangerous delay associated with laboratory tests. “Besides eliminating the laborious process of collecting and analysing samples, the biosensor’s primary innovation is in its tremendous service to public health: no longer will there be a risk of contamination not being discovered until several days after an outbreak,” says Gustav Skands.
The sensor is expected to be commercially available sometime next year.