Scientists design custom nanoparticles with new 'stencil' method

Nano-sized particles already make bicycles and tennis rackets lighter and stronger, protect eyeglasses from scratches, and help direct chemotherapy drugs to cancer cells. But their usefulness depends on being able to precisely sculpt them into the right configurations—no easy task when they're so tiny that thousands of them could fit into the thickness of a sheet of paper.

In a study published Dec. 3 in Nature Materials, University of Chicago scientists unveiled an innovative technique to push the boundaries of making such nanoparticles. They apply a coating which covers up parts of the nanoparticle, which allows them to coat new molecules on only the exposed surfaces—a bit like a stencil and a can of spray paint.