title: Label-free silicon photonic biosensor system with integrated detector array.
abstract: An integrated, inexpensive, label-free photonic waveguide biosensor system with multi-analyte capability has been implemented on a silicon photonics integrated circuit from a commercial CMOS line and tested with nanofilms. The local evanescent array coupled (LEAC) biosensor is based on a new physical phenomenon that is fundamentally different from the mechanisms of other evanescent field sensors. Increased local refractive index at the waveguide's upper surface due to the formation of a biological nanofilm causes local modulation of the evanescent field coupled into an array of photodetectors buried under the waveguide. The planar optical waveguide biosensor system exhibits sensitivity of 20%/nm photocurrent modulation in response to adsorbed bovine serum albumin (BSA) layers less than 3 nm thick. In addition to response to BSA, an experiment with patterned photoresist as well as beam propagation method simulations support the evanescent field shift principle. The sensing mechanism enables the integration of all optical and electronic components for a multi-analyte biosensor system on a chip.
authors.affiliation: Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523-1373, USA. yanrj@engr.colostate.edu
authors.forename: Rongjin
authors.initials: R
authors.lastname: Yan
authors.forename: Santano P
authors.initials: SP
authors.lastname: Mestas
authors.forename: Guangwei
authors.initials: G
authors.lastname: Yuan
authors.forename: Rashid
authors.initials: R
authors.lastname: Safaisini
authors.forename: David S
authors.initials: DS
authors.lastname: Dandy
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Lear
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002417:Cattle; D004867:Equipment Design; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D008962:Models, Theoretical; D055095:Optics and Photonics; D055668:Photochemical Processes; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*
chemical_list: D012710:Serum Albumin, Bovine; D012825:Silicon