Target dependence of the sensitivity in periodic nanowire-based localized surface plasmon resonance biosensors.
We investigate the target dependence of the sensitivity in a localized surface plasmon resonance (LSPR) biosensor and compare it with that of a conventional thin-film-based plasmon resonance structure. An LSPR biosensor was modeled as subwavelength periodic nanowires on a metal/dielectric substrate and targets either as bulk refractive index changes or as a biomolecular interaction that forms a monolayer. The results found that significant target-dependent variation arises in sensitivity and sensitivity enhancement by LSPR. The variation is attributed to the nonlinearity in the plasmon dispersion relation as well as the effective permittivity due to strong LSPR signals. The target dependence suggests that an LSPR structure be designed based on estimated index changes induced by target interactions. Associated broadening of resonance width can be controlled by way of profile engineering, which is discussed in connection with experimental data.
Yoon
Soon Joon
SJ
School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, Korea.
Kim
Donghyun
D
D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D006046:Gold / Q000737:chemistry; D053770:Nanowires; D055095:Optics and Photonics / Q000295:instrumentation; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation / Q000379:methods*
D006046:Gold