Michael Ladisch, distinguished professor of agricultural and biological engineering and the research coordinator, says chips containing thousands of proteins could be organized into a handheld device that could quickly and cheaply detect specific microbes, disease cells or chemicals that are either harmful or therapeutic. 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. Scientists could use the biochips to determine if certain herbal remedies actually have beneficial biochemicals that could be made into new pharmaceuticals. Although biochips containing DNA already are used to automate gene sequencing, including the human genome, many scientists have hoped to mate proteins with computer chips because proteins interact only with specific other proteins and biochemicals.
Scientists often compare the binding of proteins to a key matching a lock.
For example, a protein that binds to the cell wall of a particular bacterium 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. The device would then recognize the change in the electrical signal and confirm the presence of the bacterium in the sample. Other bacteria or molecules in the sample would not bind to the chip. The base computer chips were fabricated by Rashid Bashir, assistant professor of electrical and computer engineering, and Rafael Gomez, graduate research assistant in electrical and computer engineering, in the Purdue microelectronics fabrication facilities.