title: Enhancing surface plasmon detection using template-stripped gold nanoslit arrays on plastic films.
abstract: Nanostructure-based sensors are capable of sensitive and label-free detection for biomedical applications. However, high-throughput and low-cost fabrication techniques are the main issues which should be addressed. In this study, chip-based nanostructures for intensity-sensitive detection were fabricated and tested using a thermal-annealing-assisted template-stripping method. Large-area uniform nanoslit arrays with a 500 nm period and various slit widths, from 30 to 165 nm, were made on plastic films. A transverse magnetic-polarized wave in these gold nanostructures generated sharp and asymmetric Fano resonances in transmission spectra. The full width at half-maximum bandwidth decreased with the decrease of the slit width. The narrowest bandwidth was smaller than 10 nm. Compared to nanoslit arrays on glass substrates using electron-beam lithography, the proposed chip has a higher intensity sensitivity up to 10367%/RIU (refractive index unit) and reaches a figure of merit up to 55. The higher intensity sensitivity for the template-stripped nanostructure is attributed to a smoother gold surface and larger grain sizes on the plastic film, which reduces the surface plasmon propagation loss.
authors.affiliation: Research Center for Applied Sciences,  Academia Sinica , 128, section 2, Academia Road, Nangkang, Taipei 11529, Taiwan.
authors.forename: Kuang-Li
authors.initials: KL
authors.lastname: Lee
authors.forename: Pei-Wen
authors.initials: PW
authors.lastname: Chen
authors.forename: Shu-Han
authors.initials: SH
authors.lastname: Wu
authors.forename: Jhih-Bin
authors.initials: JB
authors.lastname: Huang
authors.forename: Sen-Yeu
authors.initials: SY
authors.lastname: Yang
authors.forename: Pei-Kuen
authors.initials: PK
authors.lastname: Wei
mesh_terms: D006046:Gold / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000295:instrumentation*; D010969:Plastics / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry; D013499:Surface Properties
chemical_list: D010969:Plastics; D006046:Gold; D012825:Silicon