The research coordinator says chips containing thousands of proteins could be organized into a device about the size of a handheld computer that could quickly and cheaply detect specific microbes, disease cells and harmful or therapeutic chemicals. Soldiers might rely on sensors on the battlefield to sound the alarm in the event of a biological or chemical attack. Farmers could place sensors in their fields to alert them to crop diseases. Medical scientists could use the biochips to investigate whether certain plants popular as folk remedies actually contain biochemicals that have beneficial biological activity, and from the findings could develop new pharmaceutical products. Although biochips containing DNA already are used to automate the sequencing of genes, including the human genome, many scientists have been interested in mating proteins with computer chips because proteins are very specific about which other proteins or biochemicals they will interact with.
Scientists often compare the binding of proteins to a key matching with a lock.
Take, for example, a protein that binds to the cell wall of a particular bacterium. That protein could be attached to the biochip. If the bacterium were present in a sample passed over the chip, it would bind to the protein, causing a detectable change in the electrical signal passing through the chip. This change in the electrical signal would be registered by the device, confirming the presence of the bacterium in the sample. Other bacteria or molecules in the sample would not bind to the chip.