THE tricks that microscopic sea creatures use to build their skeletons are
hinting at ways to construct delicate, tailor-made silica structures.
The single-celled creatures called diatoms build their cell walls from
silica, otherwise known as silicon dioxide. The silicon comes dissolved in
seawater, but how the minuscule creatures convert it into silica is a
mystery.
But now Christopher Knight and his team at the University of Illinois in
Urbana-Champaign think they have discovered its secret. They let the diatom
Navicula pelliculosa take up radioactive silicon-29, and used nuclear
magnetic resonance to track what it reacted with inside the creature. This
showed that it joined with oxygen and carbon to form a short-lived molecule no
one has seen before. They believe it鈥檚 the first carbon-silicon compound ever
found in nature.
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Knight suspects that the diatom uses the chemical as an intermediate stage in
silica production. He hopes it will eventually be possible to use the same
reaction to custom-make objects such as microporous silica sheets. By letting in
only molecules of a particular size, these might one day act as sensitive
chemical detectors.