If you need diagnostic work done these days, you typically have to provide some blood or other sample that gets shipped off to a lab somewhere. Then you wait for the results to come back. Wouldn’t it be great if you could find out the answers right away? There’s some great work being done to create “lab on a chip” devices that can do this, but they remain expensive and complex.
Researchers at McMaster University in Ontario, Canada, have a different approach in mind. They have developed very large DNA molecules that can produce a signal when in the presence of a targeted bacteria or other pathogen. They are working on a way to print these large molecules onto paper using a standard ink jet printer to create paper biosensors. You could then introduce a sample to the molecules by putting a drop on the paper, and get a nearly-instantaneous reading.
This could be helpful in diagnosing diseases and other conditions, but if the costs are low enough, other applications would become possible. For example, imagine food packaging that would change in the presence of E. coli contamination, and create a visible warning to the consumer. It would become easy to test for toxins in a water supply, or provide rapid diagnostics for patients in remote areas of under-developed countries. Printing sensors on paper could make biomarker testing quick, easy, and inexpensive.
