Nanoscale particles have an important role in the chemical and biological sciences, but efforts to make nanoparticles from borosilicate glass — which exhibits high tolerance to chemicals and solvents, combined with excellent mechanical and thermal stability — have proved unsuccessful so far. Now Martin Gijs and co-workers have shown that borosilicate nanoparticles (100–500 nm in size) can be synthesized by simply mixing a silicon–boron binary oxide solution with water to induce a vigorous exothermic phase separation in which the borosilicate nanoparticles burst out of a silica phase. In addition to potential applications in the life sciences, the nanoparticles could also be useful in ultrasonic microscopy, optics and chemical filtration membranes.

Cover design by Karen Moore

Letter p589