1] State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China [2].
Nat Commun. 2013;4:2381. doi: 10.1038/ncomms3381.
Localized surface plasmon resonance (LSPR)-based sensing has found wide applications in medical diagnosis, food safety regulation and environmental monitoring. Compared with commercial propagating surface plasmon resonance (PSPR)-based sensors, LSPR ones are simple, cost-effective and suitable for measuring local refractive index changes. However, the figure of merit (FOM) values of LSPR sensors are generally 1-2 orders of magnitude smaller than those of PSPR ones, preventing the widespread use of LSPR sensors. Here we describe an array of submicrometer gold mushrooms with a FOM reaching ~108, which is comparable to the theoretically predicted upper limit for standard PSPR sensors. Such a high FOM arises from the interference between Wood's anomaly and the LSPRs. We further demonstrate the array as a biosensor for detecting cytochrome c and alpha-fetoprotein, with their detection limits down to 200 pM and 15 ng ml(-1), respectively, suggesting that the array is a promising candidate for label-free biomedical sensing.
基于局域表面等离子体共振（LSPR）的传感技术在医学诊断、食品安全监管和环境监测等领域得到了广泛应用。与商用传播表面等离子体共振（PSPR）传感器相比，LSPR 传感器具有结构简单、成本低、适用于测量局域折射率变化等优点。然而，LSPR 传感器的品质因数（FOM）值通常比 PSPR 传感器低 1-2 个数量级，这限制了 LSPR 传感器的广泛应用。本文报道了一种具有约 108 的 FOM 的亚微米金蘑菇阵列，这与标准 PSPR 传感器的理论预测上限相当。这种高 FOM 源于 Wood 异常和 LSPRs 之间的干涉。我们进一步将该阵列用作检测细胞色素 c 和甲胎蛋白的生物传感器，其检测限分别低至 200 pM 和 15 ng ml(-1)，表明该阵列是一种很有前途的无标记生物医学传感候选者。
