On-chip photonic tweezers for bacteria capture and characterization

Researchers from Irig, LTM, and CEA-Leti have developed an almost-instant means of testing bacteria viability after a thermic shock. The new device features an optical nanocavity and two micromirrors. A laser beam bounces back and forth between the mirrors hundreds, or even thousands, of times before escaping: This resonance creates a gradient force* that attracts nearby bacteria. The viability of the bacteria alters their effect on the resonance frequency.

The new nanosystem could be used to check how bacteria react to antibiotics, reducing test times from around 48 hours of culture time in a Petri dish to mere moments. Potential benefits include more targeted use of antibiotics, lowering the risk of antibiotic resistance.

*Phenomenon discovered by the American physicist Arthur Ashkin, 2018 winner of the Nobel Prize in Physics.

Contact: emmanuel.hadji@cea.fr

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