Diffractive Optical Analysis for Refractive Index Sensing using Transparent Phase Gratings.
Diffractive Optical Analysis for Refractive Index Sensing using Transparent Phase Gratings.
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DOI：
10.1038/srep16687
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发表时间：
2015-11-18
影响因子：
4.6
通讯作者：
Varma M
中科院分区：
文献类型：
--
作者：
Kumawat N;Pal P;Varma M
我们报告了一种微图案、基于玻璃的光子传感元件的实现，该元件能够进行无标记生物传感。衍射光学分析仪基于衍射级对体积以及表面折射率变化的差异响应。差分读数可抑制信号漂移，并能够对样品池中的折射率变化进行时间分辨测定。该装置的一个显着特点是，在适当的条件下，由于多重反射衍射级之间的干涉，传感器的测量灵敏度可以提高两个数量级以上。使用该技术实现了 6 × 10−7 的噪声等效检测限 (LoD)，并且还有进一步改进的空间。
We report the implementation of a micro-patterned, glass-based photonic sensing element that is capable of label-free biosensing. The diffractive optical analyzer is based on the differential response of diffracted orders to bulk as well as surface refractive index changes. The differential read-out suppresses signal drifts and enables time-resolved determination of refractive index changes in the sample cell. A remarkable feature of this device is that under appropriate conditions, the measurement sensitivity of the sensor can be enhanced by more than two orders of magnitude due to interference between multiply reflected diffracted orders. A noise-equivalent limit of detection (LoD) of 6 × 10−7 was achieved with this technique with scope for further improvement.