title: Integrated polymer-based Mach-Zehnder interferometer label-free streptavidin biosensor compatible with injection molding.
abstract: We report the development of a Mach-Zehnder interferometer biosensor based on a high index contrast polymer material system and the demonstration of label-free online measurement of biotin-streptavidin binding on the sensor surface. The surface of the polyimide waveguide core layer was functionalized with 3-mercaptopropyl trimethoxy silane and malemide tagged biotin. Several concentrations of Chromeon 642-streptavidin dissolved in phosphate buffered saline solution were rinsed over the functionalized sensor surface by means of a fluidic system and the biotin-streptavidin binding process was observed in the output signal of the interferometer at a wavelength of 1310 nm. Despite the large wavelength and the comparatively low surface sensitivity of the sensor system due to the low index contrast in polymer material systems compared to inorganic material systems, we were able to resolve streptavidin concentrations of down to 0.1 μg/ml. The polymer-based optical sensor design is fully compatible with cost-efficient mass production technologies such as injection molding and spin coating, which makes it an attractive alternative to inorganic optical sensors.
authors.affiliation: AIT Austrian Institute of Technology GmbH, Health & Environment, Nano Systems, Donau-City-Strasse 1, 1220 Vienna, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Bruck
authors.affiliation: AIT Austrian Institute of Technology GmbH, Health & Environment, Nano Systems, Donau-City-Strasse 1, 1220 Vienna, Austria.
authors.forename: E
authors.initials: E
authors.lastname: Melnik
authors.affiliation: AIT Austrian Institute of Technology GmbH, Health & Environment, Nano Systems, Donau-City-Strasse 1, 1220 Vienna, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Muellner
authors.affiliation: AIT Austrian Institute of Technology GmbH, Health & Environment, Nano Systems, Donau-City-Strasse 1, 1220 Vienna, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Hainberger
authors.affiliation: Department of Analytical Chemistry, University of Vienna, Waehringer Strasse 38, 1090 Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Lämmerhofer
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D015374:Biosensing Techniques; D001710:Biotin / Q000031:analogs & derivatives / Q000737:chemistry; D007368:Interferometry; D011108:Polymers / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D019809:Streptavidin / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D011108:Polymers; D012821:Silanes; C066114:biotin-streptavidin complex; D001710:Biotin; D019809:Streptavidin