title: Visualization of biosensors using enhanced surface plasmon resonances in capped silver nanostructures.
abstract: We propose a method and optical design for direct visualization of label-free detection. The system, similar to a tiny spectral analyzer, is composed of a nanostructure-based surface plasmon resonance chip, linear polarizer and 532 nm laser light source. The full-width-at-half-maximum bandwidths of the enhanced surface plasmon resonances are about 5 nm. The distribution of the transmitted light from these arrays comprises a spectral image on the chip. The qualitative and quantitative analyses of the analyte can be conducted by observing the spot shift on the chip. We tested the sensing capability of the chip. The detectable surface mass density with the naked eye is about 0.476 μg cm(-2). In addition, antigen-antibody interaction experiments are conducted to verify the surface binding measurements. A monolayer protein attached on the chip can be directly observed and the concentration levels of the analyte can be estimated with the naked eye. Such plasmonic biochips can benefit sensing applications in point-of-care diagnostics.
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan. pkwei@sinica.edu.tw.
authors.forename: Kuang-Li
authors.initials: KL
authors.lastname: Lee
authors.forename: Meng-Lin
authors.initials: ML
authors.lastname: You
authors.forename: Cheng-Lin
authors.initials: CL
authors.lastname: Tsai
authors.forename: Chia-Yu
authors.initials: CY
authors.lastname: Hung
authors.forename: Shu-Yi
authors.initials: SY
authors.lastname: Hsieh
authors.forename: Pei-Kuen
authors.initials: PK
authors.lastname: Wei
mesh_terms: D036103:Nanotechnology / Q000295:instrumentation*; D055096:Optical Devices; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D012834:Silver