New Biosensor May Achieve Real-Time Monitoring

A new invention from researchers in Denmark can detect water contamination as it happens.

The device relies on a process called impedance flow cytometry. Here’s how it works, according to a report from Science Alert:

Liquid is monitored via electrodes that carry multi-frequency voltage signals, and when bacteria and particles hit the electrodes, the impedance is affected. Because the impedance change for bacteria is uniquely different from other non-organic particles, the sensor can identify with a high degree of accuracy whether or not the water is contaminated. What's more, the whole system requires very little in the way of maintenance.

There could be numerous important commercial applications for this technology, which could go to market next year. “Along with its use in hand-held devices that could be used to perform inspections at varying locations, the sensor could also be integrated into multiple interconnected unmanned water-testing stations along one waterway. If any of them detected harmful bacteria, they could instantly raise an alarm, with the network tracking the flow of the contamination,” Gizmag reported.

The technique is simple, according to materials from SBT Aqua, a company affiliated with the researchers: “A liquid sample is continuously injected into a microfluidic channel with integrated electrodes over which a multi-frequency voltage signal is applied. Bacteria and particles transition across the electrodes which results in a change in impedance.”

One of the researchers explained the promise of this device: "I believe that our product will revolutionize the way microbiological water quality measurements are made," said Erik Gustav Skand, CEO of the tech startup SBT Aqua.

For similar stories, visit Water Online’s Source Water Contamination Solutions Center.