Photonic crystal and plasmonic nanohole based label-free biodetection
Photonic crystal and plasmonic nanohole based label-free biodetection
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DOI：
10.1016/j.bios.2019.02.047
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发表时间：
2019-05-01
影响因子：
12.6
通讯作者：
Topkaya, Seda Nur
中科院分区：
文献类型：
--
作者：
Cetin, Arif E.;Topkaya, Seda Nur
光子晶体和等离子体纳米孔阵列是无标记生物检测应用的常规基底。在本文中，我们从传感能力的角度重新探讨了这些系统，并为提供强传感信号的最佳参数选择机制提供了一个全面的视角。我们首先研究了这两个系统所支持的传输共振的物理起源，这是无标记传感机制的核心，依赖于强光 - 物质相互作用。我们对这两个系统的光学和传感特性进行了广泛的理论研究，例如，光学模式的线宽、折射率灵敏度和品质因数能力。我们的理论分析为这两个系统的几何器件参数选择提供了一个经验法则方法。为了实验研究传感特性，我们通过一种基于电子束光刻的无剥离制造方法制造了这两个系统，其中等离子体纳米孔阵列是通过在声子晶体表面覆盖一层薄金属来实现的。例如，我们通过监测其光学响应中的光谱变化，展示了两个尺寸相同的系统的传感强度。我们还通过检测蛋白质单层和双层进行了无标记传感实验，其中几何参数对等离子体传感器系统有利。将高分辨率光学读出方案与多光谱数据跟踪技术相结合，我们在实验中实现了等离子体纳米孔阵列低至200皮克/毫升以及基于光子晶体的传感平台低至1纳克/毫升的可检测蛋白质浓度最小值。
Photonic crystals and plasmonic nanohole arrays are the conventional substrates for label-free biodetection applications. In this article, we readdressed these systems in terms of their sensing capability and provided a broad picture for a selection mechanism of optimum parameters providing strong sensing signals. We first investigated the physical origin of the transmission resonances supported by the two systems, which is the core of the label-free sensing mechanism, relying on strong light-matter interactions. We conducted an extensive theoretical study on optical and sensing properties of the two systems, e.g., linewidth of the optical modes, refractive index sensitivity and figure-of-merit capacities. Our theoretical analyses provided a rule-of-thumb method for the selection of geometrical device parameters of the two systems. In order to experimentally investigate the sensing properties, we fabricated the two systems via a lift-off free fabrication method based on electron beam lithography, where the plasmonic nanohole arrays are realized by covering the phonic crystal surface with a thin metal. As an example, we demonstrated the sensing strength of two systems with identical dimensions by monitoring the spectral variations within their optical responses. We also performed label-free sensing experiments through detection of protein mono- and bilayers, where the geometrical parameters favor the plasmonic sensor system. Integrating a high-resolution optical read-out scheme with a multi-spectral data tracking technique, we achieved an experimentally minimum detectable protein concentration as low as 200 pg/mL for the plasmonic nanohole array and 1 ng/mL for the photonic crystal based sensing platform.