Researchers at Liverpool University have shown that enzymes that cleave DNA are still effective when the DNA is bound to spherical gold nanoparticles. Such enzymes that are able to 'cut and paste' DNA will be essential for developing effective nanoparticles for biodiagnostics and possibly also for electronic circuits. Matthew Brust and colleagues used a site-specific 'restriction endonuclease' that cuts the double helix of DNA at a particular sequence, breaking the DNA into fragments with well-defined base pairs at each end. Future work will seek to limit the amount of bound DNA since Brust found that some of the DNA was not cleaved because of steric crowding on the surface of the nanoparticles. 

Graham McCann