Currently, there’s one major application that uses sensitive paper: home pregnancy tests. If you’ve ever bought one, you’ll know they’re expensive. That’s because the paper in them relies on a membrane, called nitrocellulose, to “catch” molecules of interest. But there’s a better way, explains researcher Daniel Ratner to CNET:
“We want to develop something to not just ask a single question but ask many personal health questions… Is there protein in the urine? Is this person diabetic? Do they have malaria or influenza?”
Instead of expensive, single-purpose paper, Ratner has been developing paper that can bind to a whole fleet of chemicals, including DNA, antibodies and sugars. To do that, his team simply coats paper in an industrial solvent in which a range of biomolecules are suspended. When the paper is exposed to a chemical that reacts with the biomolecules, you can see a distinctive change in colour. The results are published in Langmuir.
The experiments so far have used plain old office paper as a base, and the scientists are confident that in the future the sensing technology should be “ultracheap”. Who said a paperless office was the future? [Langmuir via CNET]