Portable device rapidly detects drinking water pollution

The device draws on the human body’s natural defence mechanism against metal intoxication: an organic substance in the bloodstream called a chelating agent, which can detect and bind to heavy metal ions.

After binding, it prevents the heavy metal ions from interacting with other molecules and enzymes in the body, and marks it for excretion from the body.

By combining a chelating agent with an optical measurement system, the Singapore group developed a compact and highly sensitive device that can be used to rapidly test water samples in the field. The team claims that the technology could also be integrated into appliances for domestic use, such as water filtration systems.

The new device comprises an optical fibre sensor modified with a chelating agent, and a laser that shines through it. This sensor is connected to a processing unit that displays the results of the water quality test.

In a water sample contaminated by heavy metals, the metal ions will bind to the chelating agent on the optical fibre sensor. This induces a shift in the output light spectrum, from which the device’s processing unit then calculates the concentration of heavy metals in the sample. The process takes about five minutes.