Figure 3.

(a) The schematic image of the LSPR sensor which is utilizing the non-periodically distributed nanostrucutres is presented. The randomly positioned nanostructures were used for efficiently localized the plasmonic field. The SEM image of the nanostructures is shown in green box (reproduced from [86] with permission from Elsevier); (b) The changing of resonance peak was recorded for sensing the refractive index changes when the concentrations of virus get increased on the two kinds of substrate. The material feature was measured more sensitively on the nanoisland-existed substrate than on thin film substrate as presented in graph (reproduced from [86] with permission from Elsevier); (c) To amplify the wavelength shift of LSPR sensor, gold nanoparticle-labeled antibodies were used. The conjugation of antibody-nanoparticle improves the observed binding constant and this amplification strategy provides a way to improve the sensitivity of plasmon-based bioassays, paving the way for single molecule-based detection and clinically relevant diagnostics (Reprinted with permission from [92]. Copyright 2011 American Chemical Society); (d) The maximum Δλ was 11 nm after binding of native antibiotin (dashed blue) whereas 42.7 nm of Δλ was monitored after binding of antibiotin-labeled nanoparticles (red dashed line) as illustrated in (e) (Reprinted with permission from [92]. Copyright 2011 American Chemical Society).