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Starting Small

Scientist Uses Viruses As Building Blocks For New Technology

By Deborah Smith, Science Writer

Angela Belcher is inspired by sea snails. To make their beautiful mother-of-pearl shells, the small creatures have developed a way to stack individual grains of calcium carbonate into layers so that they form a uniquely luminescent and very strong structure.

Dr Belcher, a leading American nanoscientist, also wants to manipulate atoms a few at a time, so she can build up her own completely new materials for use in computers and medical devices and for energy storage.

But how to operate at this microscopic level?

The world-first solution that the 35-year-old researcher has hit upon is to get tiny viruses to do the hard yakka for her.

"Scientists didn't invent nanoscience; organisms have been doing it for a long time," said Dr Belcher, of the Massachusetts Institute of Technology.

Viruses are a good choice for labourers, she says, because it is easy to fiddle with their DNA. "And they have evolved over millions of years to work perfectly at the nanoscale level."

A nanometer is one billionth of a metre, and nanoscience covers many areas of research that deal with nanosized particles - from quantum computers to a better sunscreen.

Dr Belcher's team has genetically engineered long, skinny viruses so they selectively bind to different kinds of nanoparticles.

Surprisingly, billions of viruses, with their loads, can self-organise to form a thin film that can be picked up with a pair of tweezers, the team found.

Dr Belcher says one potential application of this process would be to bind vaccines to virus films and dehydrate them for use in the Third World, where lack of refrigeration makes storage of liquid vaccines problematic.

Dr Belcher was a keynote speaker yesterday at a nanotechnology conference in Canberra, organised by the Australian Academy of Science.

Prince Charles is among those who have raised concerns about the safety of nanotechnology, including the fear it will lead to a catastrophe where self-assembling nanomachines devour the planet.

But Dr Belcher believes nanotechnology that mimics nature will lead to "very green chemistry", with new ways to synthesise material without producing toxic byproducts.

Her team uses a virus that only infects bacteria, called a bacteriophage. Last year, they showed bacteriophages could be genetically modified so they produced a protein on their surface that was able to bind to particles of zinc sulphide, a semi-conductor. The film made by billions of these viruses acts like the liquid crystalline films in computer displays.

In her latest research, viruses were produced that could pick up three different kinds of particles: gold, an organic dye, and a fluorescent protein. Possible applications of the process include the production of nanoscale computer chips, more efficient batteries, microscopic sensors and devices for storing DNA or drugs.