Sinibaldi Alberto, Anopchenko Aleksei, Rizzo Riccardo, Danz Norbert, Munzert Peter, Rivolo Paola, Frascella Francesca, Ricciardi Serena, Michelotti Francesco
Department of Basic and Applied Science for Engineering, Sapienza University of Rome, Via A. Scarpa 16, 00161, Rome, Italy.
Anal Bioanal Chem. 2015 May;407(14):3965-74. doi: 10.1007/s00216-015-8591-8. Epub 2015 Mar 18.
In label-free biosensing, a continuous improvement of the limit of detection is necessary to resolve the small change of the surface refractive index produced by interacting biomolecules at a very small concentration. In the present work, optical sensors based on one-dimensional photonic crystals supporting Bloch surface waves are proposed and adopted for label-free optical biosensing. We describe the implementation of an angularly resolved ellipsometric optical sensing scheme based on Bloch surface waves sustained by tantala/silica multilayers. The angular operation is obtained using a focused beam at fixed wavelength and detection of the angular reflectance spectrum by means of an array detector. The results show that the experimental limit of detection for a particular photonic crystal design is 6.5 × 10(-7) refractive index units (RIU)/Hz(1/2) and further decrease could be obtained. For the first time, we report on the practical application of this technique to a cancer biomarker protocol that aims at the detection of a specific glycoprotein (angiopoietin 2) involved in angiogenesis and inflammation processes.
在无标记生物传感中，为了分辨极低浓度下相互作用的生物分子所产生的表面折射率的微小变化，检测限的持续改进是必要的。在本工作中，提出并采用了基于支持布洛赫表面波的一维光子晶体的光学传感器用于无标记光学生物传感。我们描述了一种基于钽氧化物/二氧化硅多层膜所支持的布洛赫表面波的角度分辨椭偏光传感方案的实现。通过在固定波长下使用聚焦光束并借助阵列探测器检测角度反射光谱来实现角度操作。结果表明，对于特定光子晶体设计，实验检测限为6.5×10⁻⁷折射率单位（RIU）/Hz¹/²，并且可以进一步降低。我们首次报道了该技术在癌症生物标志物检测方案中的实际应用，该方案旨在检测参与血管生成和炎症过程的特定糖蛋白（血管生成素2）。
