title: Detection of recombinant growth hormone by evanescent cascaded waveguide coupler on silica-on-silicon.
abstract: An evanescent wave based biosensor is developed on the silica-on-silicon (SOS) with a cascaded waveguide coupler for the detection of recombinant growth hormone. So far, U -bends and tapered waveguides are demonstrated for increasing the penetration depth and enhancing sensitivity of the evanescent wave sensor. In this work, a monolithically integrated sensor platform containing a cascaded waveguide coupler with optical power splitters and combiners designed with S -bends and tapper waveguides is demonstrated for an enhanced detection of recombinant growth hormone. In the cascaded waveguide coupler, a large surface area to bind the antibody with increased penetration depth of evanescent wave to excite the tagged-rbST is obtained by splitting the waveguide into multiple paths using Y splitters designed with s -bends and subsequently combining them back to a single waveguide through tapered waveguide and combiners. Hence a highly sensitive fluoroimmunoassay sensor is realized. Using the 2D FDTD (Finite-difference time-domain method) simulation of waveguide with a point source in Rsoft FullWAVE, the fluorescence coupling efficiency of straight and bend section of waveguide is analyzed. The sensor is demonstrated for the detection of fluorescently-tagged recombinant growth hormone with the detection limit as low as 25 ng/ml.
authors: Optical Bio-Microsystems Laboratory, Department of Mechanical and Industrial Engineering, Concordia University, Montreal, Canada.
authors: Jayan
authors: J
authors: Ozhikandathil
authors: Muthukumaran
authors: M
authors: Packirisamy
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D002232:Carbocyanines / Q000737:chemistry; D002417:Cattle; D005456:Fluorescent Dyes / Q000737:chemistry; D013006:Growth Hormone / Q000032:analysis* / Q000737:chemistry; D055096:Optical Devices; D011994:Recombinant Proteins / Q000032:analysis* / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: C569686:Alexa Fluor 647; D002232:Carbocyanines; D005456:Fluorescent Dyes; D011994:Recombinant Proteins; D012822:Silicon Dioxide; D013006:Growth Hormone; D012825:Silicon