New on-chip technology enabled researchers from UC Santa Cruz and Brigham Young University to detect multiple strains of the flu virus on a single chip. The chip is composed of microfluidic channels and an intersecting optical waveguide. To detect specific biomarkers, the optofluidic chip relies on wavelength-division multiplexing whereby multiple wavelengths of light are combined and transmitted together. When molecules tagged with fluorescent targets are excited, they create wavelength-dependent spot patterns allowing for unique identification of the molecules.
To test the chip, three influenza subtypes were tagged with three fluorescent markers. Researchers were able to distinguish the three strains in a mixed sample. Subsequently, one of the influenza subtypes was tagged with a mix of the two other markers. Each influenza strain continued to yield unique spot patterns, indicating that wavelengths can be matched to more targets. In the real world, samples of flu strains would be tagged using fluorescently labeled antibodies before running through the chip.
From the study abstract in Proceedings of the National Academy of Sciences:
Optical waveguides simultaneously transport light at different colors, forming the basis of fiber-optic telecommunication networks that shuttle data in dozens of spectrally separated channels. Here, we reimagine this wavelength division multiplexing (WDM) paradigm in a novel context––the differentiated detection and identification of single influenza viruses on a chip. We use a single multimode interference (MMI) waveguide to create wavelength-dependent spot patterns across the entire visible spectrum and enable multiplexed single biomolecule detection on an optofluidic chip.
Via: UC Santa Cruz…