Rapid and sensitive diagnostic methods to identify pathogenic bacteria are essential to provide patients with appropriate antibiotic treatments and, thus, guarantee the best patient care. Nevertheless, standard approaches are often too expensive, time consuming or have limited specificity for a clinical use.

Hyun Jung Chung, Massachusetts General Hospital, USA, and colleagues developed a diagnostic method which overcomes these limitations. The new system consists of iron oxide nanoparticles that are conjugated to oligonucleotide probes binding to target bacterial nucleic acids. As these nanoparticles are magnetic, upon their binding to pathogenic DNA molecules, they form magnetic complexes which are detected using a miniaturized nuclear magnetic resonance (NMR) device.

This novel approach was able to identify numerous clinically relevant bacterial species within 2 h. Moreover, it exhibited high sensitivity and specificity. This system, therefore, constitutes an attractive tool to detect pathogens in numerous applications.

• A magneto-DNA nanoparticle system for rapid detection and phenotyping of bacteria,
  H. J. Chung, C. M. Castro, H. Im, H. Lee, R. Weissleder,
  Nature Nanotech. 2013.
  DOI: 10.1038/NNANO.2013.70