The Aggies have come up with a device to detect weewee and doodoo in pools. Read more here.
Urobilin molecules are small and diffuse quickly so they easily occupy large volumes, such as lakes and reservoirs, for example.
When mixed with zinc ions, urobilin forms a phosphorescent compound which glows green under an ultraviolet light.
In some samples, low concentrations of urobilin cause the glow to become weak.
To tackle this, the researchers used a hollow cylinder called an integrated cavity.
Water is placed inside the cylinder where it interacts with zinc ions, and a laser light is beamed into the object and onto the sample through a small hole.
The light reacts with the urobilin compound in the sample, causing it to emit a glow even at low concentrations.
The detection results appear almost instantaneously.