Nano-scale porous silicon for iPhone equates to simple, cost-effective home diagnostics

The simplest home-based medical tests might look like a silicon film set covered with a special film, one for detecting drugs in the blood, another for the proteins in the urine indicating an infection, a other for bacteria in the water, etc. Add the body fluid you want to test, take a picture with your smartphone and a special application lets you know if there is a problem or not.

That's what Sharon Weiss, Electrical Engineer, Professor Cornelius Vanderbilt of Vanderbilt University and her students have developed in her lab, combining their research on thin, nanostructured thin layers with a device that's already in use. most American adults. "The novelty lies in the simplicity of the basic idea, and the only expensive component is the smart phone," Weiss said.

"Most people know that silicon is the material of your computer, but its uses are endless," she said. "With our nanoscale porous silicon, we have created nanometric holes a thousand times smaller than your hair, which selectively captures molecules when pretreated with the appropriate surface coating, darkening silicon, which the application detects. "

Similar technology under development relies on expensive hardware that complements the smart phone. Weiss 's system uses the phone' s flash as a light source and the team plans to develop an application capable of handling all the data processing needed to confirm that the film has simply darkened with the light. addition of fluid. In addition, in the future, such a phone could replace a mass spectrometry system costing thousands of dollars. The Transportation Security Administration has hundreds at airports across the country, where it is used to detect gunpowder on hand pads.

Other home tests rely on a color change, which is a distinct chemical reaction that introduces more room for error, Weiss said.

Weiss, Ph.D. Student Tengfei Cao and his team used a biotin-streptavidin protein assay and an iPhone SE, model A1662, to test their silicon films and found that the accuracy was similar to that of the table measuring systems. They also used a 3D printed box to stabilize the phone and get standard paper measurements, but Weiss said it would not be necessary if further research and development led to a commercial release.

Their results will appear in a future edition of Analyst, one in the journal family of the Royal Society of Chemistry.