Labs on a Chip

Innovation: Portable biosensor

Available: 2008

Soon, mothers will routinely test their children at home for the flu. Doctors will screen patients for cancer and begin discussing treatment based on the immediate results. Farmers will scrutinize the health of animals, and soldiers and environmental inspectors will test the safety of air and water, without time-consuming trips to the lab.

This is the data-rich future that Dow Corning is helping create via an alliance with Genencor International. They have to make a powerful portable biosensor that–unlike today’s unwieldy equipment–will be easy to use and flexible, capable of performing multiple diagnostic tests.

The device consists of a compact, handheld reader and a quarter-sized disposable biochip. A tiny drop of blood or water (or, eventually, air converted to liquid) goes in a hole on the chip, where it comes into contact with a silicon wafer containing a series of minuscule test wells. Molecules in the blood or water sample interact with receptor molecules in the test material–such as an antibody or DNA–just as they would in the body. The molecular reaction reduces the flow of electricity in the test wells, and the reader translates that change in current into data: what’s in your blood or in the air, and, equally important, the quantity.

Kevin Ryan, Dow’s biosensor leader, expects the first device, aimed at veterinarians, to be available in a couple of years. Sensors for human use and food inspection need FDA approval, which could take several years. The promise, though, is real: life-saving data without the wait.

Biosensor Illustration

A drop of blood or water is dropped into a chip, where it interacts with receptor molecules. 

An “ion channel switch” senses the reaction, translating a reduced flow of energy into data.