Laser Nanosensor Can Detect Bacteria In Minutes

This tiny device could eventually measure tumor cells, too.

Bacterial Growth

A new matchbox-sized nanosensor can scan for the presence of bacteria and tell if an antibiotic is effective within a few minutes, rather than the days or weeks that conventional testing methods require.

Researchers at EPFL, the Swiss Federal Institute of Technology in Lausanne, developed a lever the width of a human hair that vibrates when it senses bacteria's tiniest metabolic movements. The vibrations are then measured via a laser that reflects off the lever, turning them into an electrical current that can be read by a doctor like an EKG. When the signal flattens, it means the bacteria are dead. The system is described in a paper published online this week in Nature Nanotechnology.

Bacteria On Nanolever
Longo et al.

The sensor could be used to monitor treatments of antibiotic-resistant bacteria, especially those that are slow to grow and take a long time to test with conventional methods--which involve culturing the bacteria in the lab. The researchers also suggest the technique could one day be applied to cancer treatment, to measure tumor cells in place of bacteria.