The base computer chips were first fabricated by Rashid Bashir, assistant professor of electrical and computer engineering, working with graduate student Rafael Gomez, in Purdue's microelectronics fabrication facilities. Then, working with Ladisch and his graduate students, the group successfully attached the protein avidin to the chip. Avidin binds to a vitamin called biotin, and fluorescently labeled biotin molecules did attach to the avidin embedded on the biochip.
A key element of this research was verifying that the chips actually held the proteins, Ladisch says. J. Paul Robinson, professor of biomedical engineering and immunopharmacology, used advanced microscopic techniques to detect interactions at the surface of these chips and verify the attachment of the proteins.
Bashir and his graduate students attached the two proteins to the chip by first applying an overlay onto the chips using a process known as photolithography, which is similar to lithography printing. This helped to define the channels and metal surface regions on the chip. Then the proteins were attached by using the electrical charges naturally occurring within the proteins.
A patent application for the new Purdue biochip is pending.
A paper on the biochip, "Micro-Scale Detection of Biological Species in Micro-Fluidic Chips," was presented at the Nanoscience and Nanotechnology: Shaping Biomedical Research conference at the National Institutes of Health in Bethesda, Md., on June 25.
The first non-laboratory application of the new biochips will be to develop sensors to detect the deadly pathogen Listeria monocytogenes in
Contact: Steve Tally