El-Gohary Sherif H, Choi Jong Min, Kim Nak-Hyeon, Byun Kyung Min
Appl Opt. 2014 Apr 1;53(10):2152-7. doi: 10.1364/AO.53.002152.
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.
在本研究中，我们通过引入金属-电介质-金属（MDM）堆叠结构和亚波长金属纳米光栅，研究了局部表面等离子体共振（LSPR）生物传感器的性能提升。数值结果表明，具有MDM堆叠的LSPR基底不仅能提供超过五倍的更好灵敏度，还能显著改善信号质量。虽然金膜上的金纳米光栅不可避免地导致反射率曲线宽且浅，但MDM堆叠的存在可以通过金纳米光栅处局部增强的场来防止传播表面等离子体受到干扰，最终在共振时产生一个强而深的吸收带。因此，所提出的LSPR结构可能为监测极低分子量生物分子相互作用的增强检测开辟新的可能性。
