发表机构
University of Toronto（多伦多大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过数值模拟设计了基于亚波长纳米柱的光子晶体生物传感器，利用局域光学腔模和垂直辐射损耗相消干涉实现高灵敏度与低检测限，在生物传感领域具有应用潜力。
AI 中文摘要
通过数值求解麦克斯韦方程，对由竖立在薄硅衬底层上的亚波长硅柱构成的光子晶体（PC）平板进行光学生物传感模拟，硅柱高度仅为晶格常数的1倍或1/2。在该三维结构的二维光子带隙内，嵌入了沿生物流体流动方向形成波导的局域光学腔模，其品质因子超过10^4。利用最大局域光场强度区域内的碎片化薄硅柱，实现了对分析物结合的显著灵敏度；通过垂直辐射损耗的相消干涉，获得了优异的品质因子。这使得该器件在分析物结合时间极短的情况下，兼具高灵敏度和低检测限的罕见组合。对分析物结合的灵敏度为每0.1a的分析物厚度增量，频率偏移近0.004[2πc/a]；对于特定晶格常数a=5μm、波长16.5μm的光，对背景生物流体变化的灵敏度约为4800nm/RIU。
英文摘要
Photonic-crystal (PC) slabs composed of subwavelength silicon pillars erected on a thin silicon backing layer, with heights of only one or half lattice constant, are simulated for optical biosensing by numerical solution of Maxwell's equations. Localized optical cavity modes that form waveguides in the direction of biofluid flow, with quality factors surpassing \(10^4\), are embedded within the 2D photonic band gap of the 3D structure. Remarkable sensitivity to analyte binding is achieved using fragmented thin silicon pillars in regions of maximum localized optical-field intensity. Exceptional quality factors are realized through destructive wave interference of vertical radiation loss. This provides a rare combination of high sensitivity and low limit of detection in a device with minimal time requirement for analyte binding. The sensitivity to analyte binding is a frequency shift of nearly \(0.004\,[2πc/a]\) per analyte-thickness increment \(0.1a\). The sensitivity to background biofluid change is about \(4800\) nm per refractive index unit (RIU) for a specific lattice constant \(a = 5\,μ\mathrm{m}\) using light of wavelength \(16.5\,μ\mathrm{m}\).
