Moreover, the previous genetic screening sensors were unable to identify a wide variety of target compounds and required optical tagging to detect target sequences.
Stanford University authors wrote in the study: “We introduce a label-free genetic screening platform based on high quality factor silicon nanoantennas functionalized with nucleic acid fragments.” To develop this tool, the scientists used an optical detecting technology based on metasurfaces made of small silicon boxes. These tiny silicon arrays measure approximately 500 nanometers in height, 600 nanometers in length, and 160 nanometers in width.
Silicon boxes can focus near-infrared light on their top surface thanks to the nanoantennas. “These metasurfaces consist of subwavelength nanoantennas that strongly confine light in the near field while affording precise control over the far-field scattering,” explained the study., this approach allows a basic optical microscope to measure the shift in wavelength of light emanating from each silicon block, which varies depending on the molecules on top of the boxes.
To put the tool to the test, the researchers attached 22 nucleotide-long single-stranded gene snippets to silicon boxes and submerged the array in a buffer solution.strands were introduced to the solution, they immediately joined the tethered ones, shifting the wavelength of light emitted from the surface of each box.