Technology.am (May 15, 2009) — Unlike the simple acid or alkali strips, Harvard University professor George Whitesides is making very sophisticated litmus paper. The development of cheap and simple paper diagnostics may now help revolutionise third-world medical testing.
By harnessing a photoresist technique, Whitesides created polymer-lined channels to direct and manipulate minute quantities of fluids. Chromotography paper is soaked with a light-sensitive polymer photoresist that hardens when exposed to UV light. This leaves walls inside the paper once the unexposed polymer is dissolved. “This photoresist technique is still the highest resolution we have for making channels in paper,” he says.
The stamp-sized paper devices are capable of being printed in high volumes. A single drop of blood can be channelled to different test wells containing reagents and results appear as simple colour changes, making it ideal for third world use.
“I think it’s going to be possible to do sophisticated biological chemistry and cell biology using these methods,” says Whitesides.