New Nanophotonic Sample-Testing Chip Could Detect Multiple Viruses or Cancers In Minutes

Science magazine reports:Researchers have shown how to conduct thousands of rapid molecular screenings simultaneously, using light to identify target molecules snared on top of an array of tiny silicon blocks. In theory, the tool could be used to spot 160,000 different molecules in a single square centimeter of space. Developed to spot gene fragments from the SARS-CoV-2 virus and other infectious organisms, the technology should also be able to identify protein markers of cancer and small molecules flagging toxic threats in the environment... "[P]revious sensors have not been able to detect a wide range of target molecules," from very low to very high abundance, says Jennifer Dionne, an applied physicist at Stanford University. In hopes of getting around these problems, Dionne and her colleagues turned to an optical detection approach that relies on metasurfaces, arrays of tiny silicon boxes - each roughly 500 nanometers high, 600 nanometers long, and 160 nanometers wide - that focus near-infrared light on their top surface. This focusing makes it easy for a simple optical microscope to detect the shift in the wavelength of light coming from each silicon block, which varies depending on what molecules sit on top... [T]he technique could allow doctors to detect viral infections without first having to amplify the genetic material from a patient, Dionne says. Perhaps as important, she notes, an array can be designed to reveal how much target DNA has bound, making it possible to detect in minutes not just whether a particular virus is present, but how intense the infection is. Such information could help doctors tailor their treatments. Current tests can also do this, but they normally take several hours to amplify the genetic material and quantify the results. Dionne and her colleagues have formed a company called Pumpkinseed Bio to commercialize their new detectors, specifically aimed at detecting minute levels of proteins and other molecules that can't readily be amplified to make them easier to detect. And because only a small number of silicon blocks would be needed to spot individual target molecules, researchers should be able to craft arrays to track a multitude of disease biomarkers simultaneously. "We hope to look at many disease states at the same time," says Jack Hu, a former graduate student in Dionne's lab and head of the new startup. "That's the vision." Thanks to Slashdot reader sciencehabit for sharing the article.

Read more of this story at Slashdot.