Gao Yongkang, Xin Zheming, Gan Qiaoqiang, Cheng Xuanhong, Bartoli Filbert J
Electrical and Computer Engineering Department, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
Opt Express. 2013 Mar 11;21(5):5859-71. doi: 10.1364/OE.21.005859.
We report a plasmonic interferometric biosensor based on a simple slit-groove metallic nanostructure that monitors the phase changes of surface plasmon polaritons resulting from biomolecular adsorptions. The proposed sensing scheme integrates the strengths of miniaturized plasmonic architectures with sensitive optical interferometry techniques. Sensing peak linewidths as narrow as 7 nm and refractive index resolutions of 1 × 10(-5) RIU were experimentally measured from a miniaturized sensing area of 10 × 30 µm(2) using a collinear transmission setup and a low-cost compact spectrometer. A high-density array of such interferometric sensors was also fabricated to demonstrate its potential for real-time multiplexed sensing using a CCD camera for intensity interrogation. A self-referencing method was introduced to increase the sensitivity and reduce sensor noise for multiplexing measurements. The enhanced sensing performance, small sensor footprint, and simple instrumentation and optical alignment suggest promise to integrate this platform into low-cost label-free biosensing devices with high multiplexing capabilities.
我们报道了一种基于简单狭缝-凹槽金属纳米结构的等离子体干涉生物传感器，该传感器可监测生物分子吸附导致的表面等离激元极化激元的相位变化。所提出的传感方案将小型化等离子体结构的优势与灵敏的光学干涉测量技术相结合。使用共线传输装置和低成本紧凑型光谱仪，从10×30 µm²的小型传感区域实验测量到窄至7 nm的传感峰线宽和1×10⁻⁵RIU的折射率分辨率。还制造了这种干涉传感器的高密度阵列，以展示其使用电荷耦合器件（CCD）相机进行强度询问实现实时多路复用传感的潜力。引入了一种自参考方法来提高灵敏度并降低多路复用测量的传感器噪声。增强的传感性能、小尺寸的传感器占地面积以及简单的仪器和光学对准表明，有望将该平台集成到具有高多路复用能力的低成本无标记生物传感设备中。
