AI Insight
Researchers have developed a new molecular sensing method using paired DNA strands that recognize target molecules based on their three-dimensional shape rather than just sequence complementarity. This approach adapts the sandwich assay principle, commonly used in lateral flow tests like COVID-19 home tests, but employs DNA strand pairs as the binding agents instead of antibodies. The method could enable detection of small molecules and proteins through shape recognition, expanding the range of detectable targets beyond what traditional sequence-based DNA sensing allows.
Why it matters
This technology could lead to more versatile and cost-effective diagnostic tests for detecting a broader range of molecules, including those that lack specific sequence markers. DNA-based sensors are typically more stable and easier to produce than antibody-based tests, potentially making molecular diagnostics more accessible and affordable.
Understand the Science
You have probably performed a sandwich assay before, even if you didn’t know it. Sandwich assays are the molecular sensing technology behind lateral flow tests like the at-home COVID test. After a sample is dripped onto the test strip, it combines with detector antibodies attached to tiny gold particles, which bind to any viral proteins present. When the sample reaches the test line, a second antibody anchored to the strip binds to a different site on the viral protein, creating a molecular “sandwich.” As the gold particles accumulate, the test line turns dark red, becoming visible to the naked eye.
Source: Paired DNA strands recognize shape, not just sequence, in new small-molecule sensing method