AI 中文总结
该研究提出双梯度等离激元qBIC超表面，实现水中分子振动传感的原位优化，可实时监测脂质囊泡动态，为水相生物动态研究提供单芯片策略。
AI 中文摘要
基于连续谱中的准束缚态（qBIC）的超光子平台利用强近场增强和深亚波长场限域，为表面增强红外吸收（SEIRA）光谱提供了通用框架。然而，使用qBIC超表面在水中进行实时分子传感仍具挑战性：首先，中红外区域的强水吸收会衰减qBIC并掩盖弱分析物信号；其次，传统超表面依赖离散阵列以匹配特定波长和耦合条件，增大了器件 footprint 并增加了将qBIC与分子振动共振匹配所需的制备工作量。本文提出一种带菱形谐振器的双梯度等离激元qBIC超表面，用于水中分子振动传感的原位检测，其缩放因子和非对称参数的空间编码梯度分别在1000μm×700μm的 footprint 范围内独立控制qBIC的光谱位置和辐射速率。基于该能力，实验实时监测脂质囊泡动态，即便存在不可避免的水吸收仍可分辨羰基振动特征；随后直接识别最优传感条件并追踪其在空间编码参数空间中的演化。该结果确立了一种紧凑的单芯片策略，结合吸附动力学监测、振动指纹检测与片上优化，为研究水相条件下的生物动态提供了机遇。
英文摘要
Metaphotonic platforms based on quasi-bound states in the continuum (qBICs), harnessing strong near-field enhancement and deeply subwavelength field confinement, provide a versatile framework for surface-enhanced infrared absorption (SEIRA) spectroscopy. However, real-time molecular sensing in water using qBIC metasurfaces remains challenging. First, strong water absorption in the mid-infrared region damps qBICs and obscures weak analyte signals. Second, conventional metasurfaces rely on discrete arrays targeting individual wavelengths and coupling conditions, increasing the device footprint and fabrication effort required to match the qBIC to the molecular vibrational resonance. Here, we present a dual-gradient plasmonic qBIC metasurface with diamond-shaped resonators for in situ molecular vibrational sensing in water, where spatially encoded gradients in the scaling factor and asymmetry parameter independently control the qBIC spectral positions and radiative rates, respectively, across a 1000 um x 700 um footprint. Building on this capability, we experimentally monitor lipid vesicle dynamics in real time and resolve the carbonyl vibrational signature despite the unavoidable water absorption. We then directly identify the optimal sensing condition and track its evolution across the spatially encoded parameter space. The results establish a compact single-chip strategy that combines adsorption-kinetics monitoring, vibrational fingerprint detection, and on-chip optimization, opening opportunities for investigating biological dynamics under aqueous conditions.
