SENSORS EMPLOYING INTERFERENCE OF ELECTROMAGNETIC WAVES PASSING THROUGH WAVEGUIDES HAVING FUNCTIONALIZED SURFACES

摘要

Chemical and biosensors are disclosed. An optical waveguide is used to conduct electromagnetic radiation by total internal reflection in parallel through a reference waveguide portion and at least one analyte waveguide portion. The electromagnetic radiation is then converged into an exit beam. The external surface of at least the analyte portion is covalently modified, or functionalized, relative to the reference portion. Resulting interaction of the functionalized surface with molecules comprising an analyte causes a phase change in the electromagnetic radiation passing through the analyte portion relative to the reference portion sufficient to generate a corresponding and measurable interference pattern in the exit beam. A waveguide surface is functionalized by exposure to a reagent, having molecules each comprising a nitrenogenic group and a functionalizing group, in the presence of energized charged particles such as electrons and ions, photons, or heat, which transform the nitrenogenic reagent to a nitrene intermediate. The resulting reaction causes the functionalizing groups to covalently bond to the surface. The functionalizing groups can then participate in downstream chemistry whereby any of a large variety of functional groups, including biological molecules, can be covalently bonded to the surface. Thus, the waveguide surface can be made selectively responsive to a wide variety of analytes, including cells and other biological structures.