Zeng Beibei, Gao Yongkang, Bartoli Filbert J
Electrical and Computer Engineering Department, Lehigh University, Bethlehem, PA 18015, USA.
Nanoscale. 2015 Jan 7;7(1):166-70. doi: 10.1039/c4nr05495d.
Detecting specific target analytes and differentiating them from interfering background effects is a crucial but challenging task in complex multi-component solutions commonly encountered in environmental, chemical, biological, and medical sensing applications. Here we present a simple nanoplasmonic interferometric sensor platform that can differentiate the adsorption of a thin protein layer on the sensor surface (surface effects) from bulk refractive index changes (interfering background effects) at a single sensing spot, exploiting the different penetration depths of multiple propagating surface plasmon polaritons excited in the ring-hole nanoplasmonic sensors. A monolayer of bovine serum albumin (BSA) molecules with an effective thickness of 1.91 nm is detected and differentiated from a 10(-3) change in refractive index unit for the bulk solution. The noise level of the retrieved real-time sensor output compares favorably with that of traditional prism-based surface plasmon resonance sensors, but is achieved using a significantly simpler collinear transmission geometry and a miniaturized sensor footprint.
在环境、化学、生物和医学传感应用中常见的复杂多组分溶液里，检测特定目标分析物并将其与干扰背景效应区分开来是一项至关重要但具有挑战性的任务。在此，我们展示了一种简单的纳米等离子体干涉传感器平台，该平台能够利用在环形孔纳米等离子体传感器中激发的多个传播表面等离子体激元的不同穿透深度，在单个传感点将传感器表面薄蛋白层的吸附（表面效应）与体相折射率变化（干扰背景效应）区分开来。检测到了有效厚度为1.91 nm的单层牛血清白蛋白（BSA）分子，并将其与体相溶液折射率单位10(-3)的变化区分开来。所获取的实时传感器输出的噪声水平与传统的基于棱镜的表面等离子体共振传感器相比具有优势，而且是通过显著更简单的共线传输几何结构和小型化的传感器尺寸实现的。
