title: Enhancement of field-analyte interaction at metallic nanogap arrays for sensitive localized surface plasmon resonance detection.
abstract: We investigated the near-field enhancement of a localized surface plasmon resonance (LSPR) structure based on gold nanograting pairs with a nanosized gap. The results calculated by finite-difference time-domain and rigorous coupled-wave analysis methods presented that the nanogap enclosed by two neighboring nanogratings produced significant confinement and enhancement of electromagnetic fields and allowed a sensitive detection in sensing of surface binding events. Gold gratings with a narrow gap distance less than 10 nm showed enhanced refractive index sensitivity due to the intensified optical field at the nanogap, outperforming the LSPR structure with noninteracting nanogratings. Also, we analyzed the effectiveness of using an overlap integral (OI) between analyte and local plasmon field to estimate the detection sensitivity. We found a strong correlation of field-analyte OI with far-field sensor sensitivity.
authors.affiliation: Department of Biomedical Engineering, Kyung Hee University, Yongin, South Korea.
authors.forename: Rabiatul Adawiah
authors.initials: RA
authors.lastname: Awang
authors.forename: Sherif Hamdy
authors.initials: SH
authors.lastname: El-Gohary
authors.forename: Nak-Hyeon
authors.initials: NH
authors.lastname: Kim
authors.forename: Kyung Min
authors.initials: KM
authors.lastname: Byun
mesh_terms: D006046:Gold; D053768:Metal Nanoparticles; D036103:Nanotechnology; D055620:Optical Phenomena; D020349:Surface Plasmon Resonance / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D013499:Surface Properties
chemical_list: D006046:Gold