title: Determination of the effective index and thickness of biomolecular layer by Fano resonances in gold nanogrid array.
abstract: We present an accurate method to determine the effective refractive index and thickness of biomolecular layer by using Fano resonance modes in dual-period gold nanogrid arrays. The effective refractive index changes along the x and y directions are simultaneously measured and obtained by using a modified dispersion relation. The thickness of the surface layer is calculated by a three-layer waveguide equation without any fitting parameters. The accuracy of the proposed method is verified by comparing the results with the known coated dielectric layer and self-assembly layers. The applications of this method and nanogrid chips for determining the thickness and surface concentration of antigen/antibody interactions are demonstrated.
authors.forename: Ming-Yang
authors.initials: MY
authors.lastname: Pan
authors.forename: Kuang-Li
authors.initials: KL
authors.lastname: Lee
authors.forename: Wan-Shao
authors.initials: WS
authors.lastname: Tsai
authors.forename: Likarn
authors.initials: L
authors.lastname: Wang
authors.forename: Pei-Kuen
authors.initials: PK
authors.lastname: Wei