Light scattering properties of dielectric nanostructures (DNSs) have been recently applied for biosensing. It is worth noting that, however, the application of dielectric materials as light scattering probes in the field of analysis and detection has rarely been reported, especially at the single particle level. Herein, for the first time, we use ZnO micron rods (ZnOMRs) as dark field microscope (DFM) imaging probes for single particle level optical sensing. It was found that a drastic reduction of scattering intensity of the ZnOMRs with increase of the surrounding medium's refractive index (RI), especially when illuminated by transverse electric (TE) polarized light, showing polarization-dependent RI sensitivity properties. In addition, the scattering color of the ZnOMRs gradually blue-shifted with the increase of solvents' RI, this can avoid the problem of low sensitivity of the probe with a red scattering color in the previous reports. The characteristic scattering properties and polarization-dependent RI sensitivity properties of ZnOMRs provide more possibilities for the development of new single-particle optical analytical methods.

中文翻译：

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ZnO 微米棒作为用于光学传感的单介质谐振器

介电纳米结构 (DNS) 的光散射特性最近已应用于生物传感。然而，值得注意的是，电介质材料作为光散射探针在分析和检测领域的应用鲜有报道，尤其是在单粒子水平上。在此，我们首次使用 ZnO 微米棒 (ZnOMR) 作为暗场显微镜 (DFM) 成像探针进行单粒子级光学传感。发现随着周围介质的折射率 (RI) 的增加，ZnOMR 的散射强度急剧降低，尤其是当被横向电 (TE) 偏振光照射时，显示出与偏振相关的 RI 灵敏度特性。此外，随着溶剂 RI 的增加，ZnOMRs 的散射颜色逐渐蓝移，这样可以避免之前报道中红色散射色的探针灵敏度低的问题。ZnOMR 的特征散射特性和偏振相关 RI 灵敏度特性为开发新的单粒子光学分析方法提供了更多可能性。