LEFT: The system being developed by UH Cullen College of Engineering researchers diagnoses disease by blocking holes with pathogens and some other connected material, in this case silver particles, preventing light from shining through. RIGHT: This is a close-up of nanoholes blocked by these particles. Credit: Jiming Bao Research Group
While there already highly accurate methods of detecting all sorts of diseases, being able to reduce the size, cost, and ease of use of diagnostic devices can help spot disease earlier, get more people screened, and improve the effectiveness of therapy. Researchers at University of Houston have developed a new device that, with the help of a smartphone, can detect diseases that have known antibodies against them.
The system relies on a gold plate with thousands of holes, each 600 nanometers wide, created within its surface. To test for a disease, antibodies that are disease-specific are spread into the holes within the plate. Then a body fluid that is being tested is dripped over the plate, allowing antibodies within the holes to stick to the pathogen being searched for. To make the test readable, a solution with the same antibodies, but with enzymes that produce silver nanoparticles attached, is poured over the plate. The antibodies again stick to the pathogen, but this time the silver nanoparticles produced within fifteen minutes after the reaction are able to block holes within the plate so that light cannot pass through. A simple microscope can be used to visualize the resulting plate to see how many holes become opaque.
The researchers envision the final component being performed using a smartphone with a special lens attachment to quickly count the opaque holes. The whole process takes about 20 minutes and by having different holes contain different antibodies, the same plate should be able to detect a variety of diseases.
Study in ACS Photonics: Transmissive Nanohole Arrays for Massively-Parallel Optical Biosensing…
University of Houston: Diagnosing diseases in real time with smartphones…