A quicker, cheaper SARS virus detector -- one easily customizable for oth...( Members of a USC-led research team s...)

Members of a USC-led research team say they've made a big improvement in a new breed of electronic detectors for viruses and other biological materials one that may be a valuable addition to the battle against epidemics.

It consists of a piece of synthetic antibody attached to a nanowire that's attached to an electrical base, immersed in liquid.

If the protein the antibody binds to is present in the liquid, it will bind to these antibodies, immediately creating a sharply measurable jump in current through the nanowire.

The basic principle of nanotube and nanowire biosensors for protein detection was first demonstrated in 2001, but the new design by a team headed by Zhongwu Chou and Mark Thompson of the University of Southern California uses two new elements.

First, it takes advantage of bioengineered synthetic antibodies, much, much smaller versions of the natural substances that are designed to bind with a specific protein and only that protein.

Second, it uses indium oxide (In2O3) nanowires instead of silicon and other materials previously tried. Metal oxides, according to a new study published in ACSNano, do not, unlike silicon, develop "an insulating native oxide layer that can reduce sensitivity."

The result, according to the paper, is a device that can detect its target molecules with a sensitivity as great as the best alternative modes, do so more rapidly and without use of chemical reagents.

It is also potentially considerably cheaper than alternatives.

"We believe," the authors write, "that nanowire bisensor devices functionalized with engineered proteins can have important applications ranging from disease diagnosis to homeland security."

Additionally, the system can be useful in basis research, in helping to establish certain important parameters for two-part biological systems like the antibody/target protein pair.

The protein the prototype system d
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