title: Photonic crystal nanostructures for optical biosensing applications.
abstract: We present the design, fabrication and optical investigation of photonic crystal (PhC) nanocavity drop filters for use as optical biosensors. The resonant cavity mode wavelength and Q-factor are studied as a function of the ambient refractive index and as a function of adsorbed proteins (bovine serum albumin) on the sensor surface. Experiments were performed by evanescent excitation of the cavity mode via a PhC waveguide. This in turn is coupled to a ridge waveguide that allows the introduction of a fluid flow cell on a chip. A response of partial delta lambda/delta c=(4.54+/-0.66)x10(5)nm/M is measured leading to a measured detection limit as good as Delta m=4.0+/-0.6 fg or Delta m/Delta A=(4.9+/-0.7)x10(2)pg/mm(2)in the sensitive area.
authors.affiliation: Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 3, D-85748 Garching, Germany. dorfner@wsi.tum.de
authors.forename: D
authors.initials: D
authors.lastname: Dorfner
authors.forename: T
authors.initials: T
authors.lastname: Zabel
authors.forename: T
authors.initials: T
authors.lastname: Hürlimann
authors.forename: N
authors.initials: N
authors.lastname: Hauke
authors.forename: L
authors.initials: L
authors.lastname: Frandsen
authors.forename: U
authors.initials: U
authors.lastname: Rant
authors.forename: G
authors.initials: G
authors.lastname: Abstreiter
authors.forename: J
authors.initials: J
authors.lastname: Finley
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D017076:Computer-Aided Design; D003460:Crystallization / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000295:instrumentation*; D055096:Optical Devices; D017785:Photons; D012031:Refractometry / Q000295:instrumentation*