Advancements in molecular screening technology are opening up new possibilities for quick and cost-effective disease diagnostics. A team of researchers has developed a tool that can conduct simultaneous rapid molecular screenings for thousands of molecules using light. Groundbreaking in its design, the tool uses tiny silicon blocks on which target molecules are trapped and then detected by light. This revolutionary technology could conceivably spot 160,000 different molecules in a square centimeter.
Detection of Gene Fragments
This new approach was designed to spot gene fragments from SARS-CoV-2, amongst other infectious organisms, but it has potential beyond that. The tool could also identify protein markers of cancer and flag toxic threats in the environment. “This technology could have a big role to play in how we detect things in the environment,” says Chris Scholin, a molecular biologist and president and CEO of the Monterey Bay Aquarium Research Institute.
Counterpointing existing genetic tests that hinge on measuring light absorption or emission from probe molecules, this new method highlights target genes without the need for amplifying techniques such as polymerase chain reaction, which significantly reduces the cost and time of the tests. “Previous sensors have not been able to detect a wide range of target molecules,” comments Jennifer Dionne, an applied physicist at Stanford University, who sees this new tool as approaching the problem differently.
Tiny Silicon Boxes Test Genetics
The Stanford team’s novel approach uses an optical detection method relying on metasurfaces, arrays of tiny silicon boxes—each around 500 nanometers high, 600 nanometers long, and 160 nanometers wide—that focus near-infrared light on their top surface. The wavelength of light coming from each silicon block varies, depending on what molecules are present, making detection straightforward.
After testing, researchers found that the setup could detect the presence of as few as 4,000 copies of target genes per microliter, showcasing its high sensitivity. Importantly, not only could the tool detect whether a virus is present, but it can also determine the intensity of the infection in a matter of minutes, a feature that greatly aids doctors in tailoring treatments.
A Big Win for Innovation
Scholin points to another compelling use for this new tool: tracking molecules outside the lab. For instance, detecting toxic algae in waterways, a job that usually involves time-consuming lab work could be expedited significantly. Another intriguing option would be tethering antibodies on top of the silicon blocks to directly grab corresponding antigens, pushing the technology’s medical applications even further.
A new start-up, Pumpkinseed Bio, is looking to commercialize these detectors, hoping to track multiple disease biomarkers at the same time. “We hope to look at many disease states at the same time,” says Jack Hu, head of the new start-up. This vision of a rapid, compact, and amplification-free molecular assay technology offers enormous potential and could revolutionize how we detect and diagnose diseases.
