On-chip nanotweezers have been developed that can trap and manipulate individual bacteria and infectious viruses using a minimal amount of optical power. The device is anticipated to speed the discovery of bacteriophages that can eradicate specific infection- or disease-causing bacteria, which are increasingly outpacing the power of pharmaceutical solutions.

The device uses light to manipulate and identify individual bacteriophages without the need for chemical labels or bioreceptors, accelerating phage-based therapies that can treat antibiotic-resistant bacterial infections. A highly focused laser beam holds and manipulates microscopic and sub-microscopic targets in three dimensions, creating a gradient force that attracts the particles toward a high-intensity focal point and holding them in place without physical contact.

Researchers from École Polytechnique Fédérale de Lausanne (Switzerland), Lausanne University Hospital (Switzerland) and Université Grenoble Alpes (France) built nanotweezers embedded in an optofluidic device that integrates optical and fluidic technologies on a single chip. The chip contains silicon-based photonic crystal cavities as the nanotweezers, forming tiny traps that steer the phages into position using a light-generated force field. The system allows precise control of single bacteria and single viruses to generate information about the trapped microorganisms in real-time.

In addition to phage therapy, the approach described in the journal Small can broaden rapid testing in other arenas of microbiological research and experimentation.