The system is the brainchild of Jiming Bao, assistant professor of electrical and computer engineering, and Richard Willson, Huffington-Woestemeyer Professor of Chemical and Biomolecular Engineering. It was created through grants from the National Institutes of Health and The Welch Foundation, and was featured in February in ACS Photonics.
This device, like essentially all diagnostic tools, relies on specific chemical interactions that form between something that causes a disease – a virus or bacteria, for example – and a molecule that bonds with that one thing only, like a disease-fighting antibody. A bond that forms between a strep bacteria and an antibody that interacts only with strep, for instance, can support an ironclad diagnosis.
To detect these chemical interactions quickly, cheaply and easily, Bao and Willson have developed a simple glass slide and a thin film of gold with thousands of holes poked in it.
To create the slide, Bao starts with a standard slide covered in a light-sensitive material known as a photoresist. A laser is then used to create a series of interference fringes – basically lines – on the slide, which then rotates the slide 90 degrees and creates another series of interference fringes. The intersections of these two sets of lines creates a fishnet pattern of UV exposure on the photoresist. The photoresist is then developed and washed away.
While most of the slide is then cleared, the spots surrounded by intersecting laser lines – the 'holes' in the fishnet – remain covered, basically forming pillars of photoresist.