Plasmonic metal-dielectric-metal stack structure with subwavelength metallic gratings for improving sensor sensitivity and signal quality.
In this study, we investigated the performance improvement of a localized surface plasmon resonance (LSPR) biosensor by incorporating a metal-dielectric-metal (MDM) stack structure and subwavelength metallic nanograting. The numerical results showed that the LSPR substrate with a MDM stack can provide not only a better sensitivity by more than five times but also a notably improved signal quality. While the gold nanogratings on a gold film inevitably lead to a broad and shallow reflectance curve, the presence of a MDM stack can prevent propagating surface plasmons from interference by locally enhanced fields excited at the gold nanogratings, finally resulting in a strong and deep absorption band at resonance. Therefore, the proposed LSPR structure could potentially open a new possibility of enhanced detection for monitoring biomolecular interactions of very low molecular weights.
Sherif H
SH
El-Gohary
Jong Min
JM
Choi
Nak-Hyeon
NH
Kim
Kyung Min
KM
Byun
D001704:Biopolymers / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D008027:Light; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry*; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation; D059629:Signal-To-Noise Ratio; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
D001704:Biopolymers; D006046:Gold