The covalent bonds that string DNA's nucleotide subunits together are tough, so breaking them requires high temperatures or a catalyst. Now Fabrizio Mancin and Paolo Scrimin at the University of Padova in Italy and their colleagues describe how to make a DNA-cleaving catalyst that works 100 times faster than one of the most efficient synthetic alternatives.
Their method relies on self-assembling sulphur-containing ligands. These are spread across a surface of gold nanoparticles and attach many zinc-based catalysts to each nanoparticle. Because this generates many catalytic sites close together, the substance can cut both strands of DNA at the same point, which enzymes find easy but artificial catalysts have not previously managed.