A team of German scientists has succeeded in creating what they call DNA ‘velcro’ to bind and then separate nanoparticles. Nanoscientists are already busily constructing novel materials. This experiment could lead, one day, to ‘self-constructing’ materials.
Based at the University of Dortmund, Christof Niemeyer and his team used strands of artificial DNA – the so-called ‘king of molecules’ – to attach gold nanoparticles together before separating them again. Each gold particle, measuring just 15 nanometres across, was attached using sulphur to the centre of a DNA strand.
Attaching nanoparticles by sticking them to complementary strands of DNA – which bind together depending on their chemical ‘bases’ – is a tried-and-tested technique. However, until now, no one had managed to re-separate them.
The way the Dortmund researchers achieved this was by ‘bridging’ together two gold particles using a third strand of DNA that complements both. This just left the problem of how to separate the gold particles once the bridge was firmly in place. Niemeyer's team developed the bridging strand of DNA to behave like ‘velcro’ – with one end longer than the other and the tip left hanging loose.
Quantum leap for European science
Such selective binding nanoparticles could provide a way to construct complex nanostructures one piece at a time. These materials could have novel electrical and optical properties that are currently unattainable through conventional chemistry. Being able to separate these materials again – i.e. unbinding them – would offer even greater flexibility. Niemeyer believes that, one day, it could be used to modify nanostructures after construction.
Nanoscience is the revolutionary new field that adopts a ‘bottom-up’ approach, taking atoms as the point of departure from which to ‘artificially’ create molecular nanosystems with very specific properties. It operates on the nanoscopic level – one billionth of a metre.
Research in this area has amazing potential for molecular and quantum computers that will take processing power to previously undreamt of heights. It also has major applications in biomedicine and the creation of environmentally friendly materials.
Under its Sixth Framework Programme (FP6), the EU has dedicated some ˆ1.3 billion to help Europe achieve a critical mass in the nanotechnologies and nanosciences.