Effect of resonant localized plasmon coupling on the sensitivity enhancement of nanowire-based surface plasmon resonance biosensors

Abstract

A nanowire-based surface plasmon resonance (SPR) is investigated as a structure that offers improved sensor performance. The results calculated by rigorous coupled-wave analysis on a model using a hexanedithiol self-assembled monolayer (SAM) indicate that the resonant coupling between localized surface plasmons (LSPs) of nanowires affects the sensitivity enhancement substantially, while the LSP resonance in a single nanowire also contributes. SPR characteristics change significantly by applying a SAM, which can give rise to zero sensitivity for a given SAM. The results suggest that a properly designed nanowire-based SPR biosensor can enhance sensitivity by an order of magnitude with reasonable detection properties.

Sensitivity Enhancement for Surface Plasmon Resonance Imaging Biosensor by Utilizing Gold–Silver Bimetallic Film Configuration

“…For the first mode, the metallic film is illuminated by polychromatic light with incident angle fixed, and the refractive index information of the medium on the metal layer surface is obtained by measuring the surface plasmon resonance wavelength [6,7]. For the second mode, the wavelength of incident light is fixed, and the refractive index change is obtained by measuring the change of the resonance incident angle [8][9][10]. For the third mode, both the wavelength and the incident angle are fixed, and the refractive index information is obtained by measuring the intensity change of the reflected light [11].…”

Enhanced Detection Sensitivity of Surface Plasmon Resonance Biosensing Based on Colocalized Target Molecules and Evanescent Fields

“…이에 대하여, 최근 플라스몬을 여기시키는 금속 박막 상에 나노구조를 형성하여 플라스몬을 국소화(localize)시키고 이 를 이용하여 감도의 개선을 이루고자 하는 접근 방법이 많은 관심을 받고 있다. 이와 관련하여 2차원 나노격자 구조에서 의 감도개선 효과에 대한 이론적 연구가 진행되었고 [9][10] , 격 자 상에서 단분자층의 형성 또는 DNA 결합 등 다양한 분자 변화를 측정한 결과가 보고되었으며 [12,13] , 금나노입자로 DNA분자를 기능화시킨 후 나노구조에서 측정하고자 하는 시도가 있었다 [14] . 불행히도 표면의 국소화만을 기반으로 한 이러한 접근방법을 이용하여 10배 이상의 감도 개선을 이루 는 것이 쉽지 않은 것으로 보인다.…”

Ultrasensitive graphene coated SPR sensor for biosensing applications

“…Several new approaches have been suggested to improve the sensitivity of SPR sensors over the last two decades 2,3 . Most of them are based on creating nanoparticles 4 , nanowires 5 , nanorings 6 nanoholes 2 and nanoslits 7 on the metal surface to enhance the localized E-field and therefore, it is quite challenging to have control over their optical properties 8 .…”