A compact optical device has been developed that can rapidly and sensitively detect biomarkers in urine and has promise for developing simple point-of-care diagnostics of cancer and other diseases.
Micro ribonucleic acids (miRNAs) are a newly discovered class of short, about 19 to 24 nucleotides in length, fragments of noncoding RNAs that are useful biomarkers for diagnosing various diseases, including cardiac disease and some cancers. Since they are surprisingly well preserved in fluids such as urine and blood, their detection is well suited to a rapid, point-of-care method.
Bioengineers at the Agency for Science, Technology and Research (Singapore) have devised a silicon photonic biosensor that can detect tiny changes in the phase of a light beam caused by hybridization between an immobilized DNA probe and target miRNAs in a sample. A laser beam travels through a waveguide, which splits into two arms: a sensing arm in which the light interacts with the sample and a reference arm.
Micro ribonucleic acids (miRNAs) are a newly discovered class of short, about 19 to 24 nucleotides in length, fragments of noncoding RNAs that are useful biomarkers for diagnosing various diseases, including cardiac disease and some cancers. Since they are surprisingly well preserved in fluids such as urine and blood, their detection is well suited to a rapid, point-of-care method.
Bioengineers at the Agency for Science, Technology and Research (Singapore) have devised a silicon photonic biosensor that can detect tiny changes in the phase of a light beam caused by hybridization between an immobilized DNA probe and target miRNAs in a sample. A laser beam travels through a waveguide, which splits into two arms: a sensing arm in which the light interacts with the sample and a reference arm.
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Image: Schematic diagram of the MZI biosensor system for miRNA detection.
(a) TEM image of the cross section of a silicon nitride slot wave guide; SEM images of
(b) a strip-slot wave guide mode converter and (c) a silicon nitride grating coupler.
(d) Image of MZI biosensor platform
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