Biochip could detect multiple viruses, cancers, or toxins in minutes

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"... Now, 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. ...
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. ...
So the technique could allow doctors to detect viral infections without first having to amplify the genetic material from a patient ..."

From the abstract:

"Genetic analysis methods are foundational to advancing personalized medicine, accelerating disease diagnostics, and monitoring the health of organisms and ecosystems. Current nucleic acid technologies such as polymerase chain reaction (PCR) and next-generation sequencing (NGS) rely on sample amplification and can suffer from inhibition. Here, we introduce a label-free genetic screening platform based on high quality (high-Q) factor silicon nanoantennas functionalized with nucleic acid fragments. Each high-Q nanoantenna exhibits average resonant quality factors of 2,200 in physiological buffer. We quantitatively detect two gene fragments, SARS-CoV-2 envelope (E) and open reading frame 1b (ORF1b), with high-specificity via DNA hybridization. We also demonstrate femtomolar sensitivity in buffer and nanomolar sensitivity in spiked nasopharyngeal eluates within 5 minutes. Nanoantennas are patterned at densities of 160,000 devices per cm2, enabling future work on highly-multiplexed detection. Combined with advances in complex sample processing, our work provides a foundation for rapid, compact, and amplification-free molecular assays."

Biochip could detect multiple viruses, cancers, or toxins in minutes | Science | AAAS Bumpy silicon array reveals presence of tiny amounts of DNA—and potentially other types of molecules—without first making copies

Rapid genetic screening with high quality factor metasurfaces (open access)

Fig. 1: Design of high-Q sensors.