College of Science, Minzu University of China, Beijing 100081, China.
Sensors (Basel). 2022 Aug 27;22(17):6467. doi: 10.3390/s22176467.
A novel all-pass slot microring resonator (SMRR), intended for label-free optical biosensing based on silicon-on-insulator platforms, is proposed. The sensor consists of a bent asymmetric directional coupler and an asymmetric-slot microring waveguide. The appropriate slot width of 140 nm is identified by the three-dimensional finite-difference time-domain (3D-FDTD) method for better light-matter interaction in applications. According to numerical calculations, the SMRR sensor with a footprint of 10 µm × 10 µm has a concentration sensitivity of 725.71 pm/% for sodium chloride (NaCl) solutions. The corresponding refractive index sensitivity is 403 nm/RIU (refractive index unit), which is approximately six times greater than that of traditional microring resonator sensors. A low detection limit of 0.129% is also achieved. This SMRR is an excellent candidate for label-free optical biosensors due to its compact structure and excellent sensing capability.
提出了一种新型的全通隙槽微环谐振器（SMRR），用于基于绝缘体上硅平台的无标记光学生物传感器。该传感器由弯曲不对称定向耦合器和非对称槽微环波导组成。通过三维有限差分时域（3D-FDTD）方法确定了合适的 140nm 槽宽，以在应用中实现更好的光物质相互作用。根据数值计算，具有 10µm×10µm 足迹的 SMRR 传感器对氯化钠（NaCl）溶液的浓度灵敏度为 725.71pm/%。相应的折射率灵敏度为 403nm/RIU（折射率单位），大约是传统微环谐振器传感器的六倍。还实现了 0.129%的低检测限。由于其紧凑的结构和出色的传感性能，这种 SMRR 是无标记光学生物传感器的优秀候选者。
