Guangdong Provincial Key laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 210632, China.
Nanoscale. 2017 Oct 12;9(39):14929-14936. doi: 10.1039/c7nr05032a.
The feasibility of a localized surface plasmon resonance (LSPR) enhanced sensor based on raspberry-like nanosphere functionalized silica microfibers has been proposed and experimentally demonstrated. The extinction of single Ag (or Au) nanoparticles usually occurs at visible wavelengths. Nevertheless, a LSPR enhancement at near infrared wavelengths has been achieved by constructing raspberry-like meso-SiO nanospheres with noble metal nanoparticle cluster coating. The nanosphere coating captures γ-amino-butyric acid (GABA) targets through size selectivity and enhances the sensitivity by the LSPR effect. The gathering of GABA on the sensor surface translates the concentration signal to the information of refractive index (RI). Silica microfiber perceives the RI change and translates it to optical signal. The LSPR effect enhances the optical sensitivity by enhancing the evanescent field on the microfiber surface. This combination presents the lowest limit of detection (LOD) of 10 M (three orders lower than that without LSPR enhancement). It could fully afford the detection of ultra-low GABA concentration fluctuation (which is important for determining a variety of neurological and psychiatric disorders). The inherent advantages of the proposed sensors, including their ultra-sensitivity, low cost, light weight, small size and remote operation ability, provide the potential to fully incorporate them into various biomedical applications.
提出并实验验证了一种基于覆盆子状纳米球功能化二氧化硅微光纤的局域表面等离子体共振（LSPR）增强传感器的可行性。单个 Ag（或 Au）纳米粒子的消光通常发生在可见光波长范围内。然而，通过构建具有贵金属纳米颗粒簇涂层的覆盆子状介孔 SiO 纳米球，可以实现近红外波长的 LSPR 增强。纳米球涂层通过尺寸选择性捕获γ-氨基丁酸（GABA）靶标，并通过 LSPR 效应增强灵敏度。GABA 在传感器表面的聚集将浓度信号转换为折射率（RI）的信息。二氧化硅微光纤感知 RI 的变化并将其转换为光学信号。LSPR 效应通过增强微光纤表面的消逝场来增强光学灵敏度。这种组合的最低检测限（LOD）为 10 M（比没有 LSPR 增强时低三个数量级）。它可以完全满足超低 GABA 浓度波动的检测需求（这对于确定各种神经和精神疾病非常重要）。所提出的传感器具有固有优势，包括超高灵敏度、低成本、重量轻、体积小和远程操作能力，为它们完全集成到各种生物医学应用中提供了潜力。
