Droplets of liquid crystals - found in our everyday electronic displays - could be used to detect bacterial contamination in water, a new study has found.
When suspended in water, the molecules in a liquid crystal droplet normally form chains that wrap around the droplet.
But a team led by Nicholas Abbott from the University of Wisconsin-Madison and coworkers has shown that endotoxin - considered to be key indications of bacterial infection - from gram-negative bacteria like Escherichia coli reorders the liquid-crystal droplets, causing a visible defect to form at their centers.
Thus, according to Abbot, only the "poles" of the droplet, where the longitudinal chains of its molecules meet up, need to contact the toxins to produce the realignment.
That suggests liquid crystals can detect endotoxins at concentrations 10 times as low as currently possible.
"The surprise was that we could trigger this ordering transition with such a small number of molecules," New Scientist quoted Abbott as saying.
It is hoped that one day, liquid crystal droplets could help ensure the safety of saline and other injectable medical fluids.