Label-free biosensing using a photonic crystal structure in a total-internal-reflection geometry.
Label-free biosensing using a photonic crystal structure in a total-internal-reflection geometry.
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DOI：
10.1117/12.808369
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发表时间：
2009-02-16
期刊：
影响因子：
--
通讯作者：
Norris TB
中科院分区：
文献类型：
--
作者：
Guo Y;Ye JY;Divin C;Thomas TP;Myc A;Bersano-Begey TF;Baker JR;Norris TB
提出并研究了一种基于全内反射结构的一维光子晶体光学生物传感器的无标记生物传感应用。这种简单的配置在顶层形成了一个微型法布里-珀罗谐振器，它提供了一个窄的光学谐振，以实现无标记的，高灵敏度的测量，用于检测表面上分析物的存在或增强的倏逝场中周围介质的折射率变化;同时，它采用了一个开放的传感表面，用于实时生物分子结合检测。实验表明，该传感器的高灵敏度的本体溶剂的折射率变化，吸附在传感表面上的分子膜，和实时分析物结合，测量两个光子晶体共振的光谱位移和差分反射测量中的强度比的变化。获得了7×10−8 RIU的本体溶剂折射率、6×10−5 nm的分子层厚度和24 fg/mm 2的质量密度的检测限，这代表了相对于最先进的基于表面等离子体共振（SPR）的系统的显著改进。因此，PC-TIR传感器被视为用于高灵敏度和精确生物分子检测的有前途的技术平台。
A novel optical biosensor using a one-dimensional photonic crystal structure in a total-internal-reflection geometry (PC-TIR) is presented and investigated for label-free biosensing applications. This simple configuration forms a micro Fabry-Perot resonator in the top layer which provides a narrow optical resonance to enable label-free, highly sensitive measurements for the presence of analytes on the sensing surface or the refractive index change of the surrounding medium in the enhanced evanescent field; and at the same time it employs an open sensing surface for real-time biomolecular binding detection. The high sensitivity of the sensor was experimentally demonstrated by bulk solvent refractive index changes, ultrathin molecular films adsorbed on the sensing surface, and real-time analytes binding, measuring both the spectral shift of the photonic crystal resonance and the change of the intensity ratio in a differential reflectance measurement. Detection limits of 7×10−8 RIU for bulk solvent refractive index, 6×10−5 nm for molecular layer thickness and 24 fg/mm2 for mass density were obtained, which represent a significant improvement relative to state-of-the-art surface-plasmon-resonance (SPR)-based systems. The PC-TIR sensor is thus seen to be a promising technology platform for high sensitivity and accurate biomolecular detection.