Locally Functionalized Short-Range Ordered Nanoplasmonic Pores for Bioanalytical Sensing
Locally Functionalized Short-Range Ordered Nanoplasmonic Pores for Bioanalytical Sensing
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DOI：
10.1021/ac902925e
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发表时间：
2010-03-01
影响因子：
7.4
通讯作者：
Hook, Fredrik
中科院分区：
文献类型：
--
作者：
Jonsson, Magnus P.;Dahlin, Andreas B.;Hook, Fredrik
基于金属薄膜上的短程有序纳米孔和离散金属纳米颗粒的纳米等离子体传感器可以提供类似的传感性能。然而，穿孔金属薄膜的独特之处在于，这些孔可以被设计成穿透衬底，从而也实现了纳米流体通道的作用。本文提出了一种基于短程有序纳米等离子体孔（直径150 nm）穿透硅晶片上由金和氮化硅（SiN）组成的薄（约250 nm）多层膜的生物分析传感概念。此外，还提出了一种制造方案，可以在单个晶圆上并行生产多个（超过50个）独立的传感器芯片或超过1000个独立的纳米等离子体膜。再加上对这种短程有序纳米孔的敏感性定位，该结构提供了尺寸为100 x 100 μ m(2)的二维纳米流体网络，每个纳米通道都有纳米等离子体活性区域。开发了一种材料特异性表面修饰方案，以促进目标分子仅在光学活性金区域上的特异性结合，同时抑制在SiN上的非特异性吸附。利用该方案，并通过监测结构的等离子体共振的时间变化，我们证明了在低于190 ms的时间分辨率下，流通过纳米等离子体感应特定生物识别反应的信噪比约为50。在流动条件下，摄取被证明比停滞条件下至少快1个数量级，同时仍将样品消耗保持在最低限度。
Nanoplasmonic sensors based on short-range ordered nano-holes in thin metal films and discrete metal nanoparticles are known to provide similar sensing performance. However, a perforated metal film is unique in the sense that the holes can be designed to penetrate through the substrate, thereby also fulfilling the role of nanofluidic channels. This paper presents a bioanalytical sensing concept based on short-range ordered nanoplasmonic pores (diameter 150 nm) penetrating through a thin (around 250 nm) multilayer membrane composed of gold and silicon nitride (SiN) that is Supported on a Si wafer. Also, a fabrication scheme that enables parallel production of multiple (more than 50) separate sensor chips or more than 1000 separate nanoplasmonic membranes on it single wafer is presented. Together with the localization of the sensitivity to within such short-range ordered nanoholes, the structure provides it two-dimensional nanofluidic network, sized in the order of 100 x 100 mu m(2), with nanoplasmon active regions localized to each individual nanochannel. A material-specific surface-modification scheme was developed to promote specific binding of target molecules on the optically active gold regions only, while suppressing nonspecific adsorption on SiN. Using this protocol, and by monitoring the temporal variation in the plasmon resonance of the structure, we demonstrate flow-through nanoplasmonic sensing of specific biorecognition reactions with a signal-to-noise ratio of around 50 at a temporal resolution below 190 ms. With flow, the uptake was demonstrated to be at least 1 order of magnitude faster than under stagnant conditions, while still keeping the sample consumption at a minimum.