State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China.
Research Center for Humanoid Sensing, Zhejiang Lab, Hangzhou 311121, China.
Lab Chip. 2023 Nov 7;23(22):4901-4908. doi: 10.1039/d3lc00499f.
Single-nanoparticle detection has received tremendous interest due to its significance in fundamental physics and biological applications. Here, we demonstrate an optical nanofibre-enabled microfluidic sensor for the detection and sizing of nanoparticles. Benefitting from the strong evanescent field outside the nanofibre, a nanoparticle close to the nanofibre can scatter a portion of the field energy to the environment, resulting in a decrease in the transmitted intensity of the nanofibre. On the other hand, the narrow and shallow microfluidic channel provides a femtoliter-scale detection region, making nanoparticles flow through the detection region one by one. By real-time monitoring of the transmitted intensity of the nanofibre, the detection of a single polystyrene (PS) nanoparticle as small as 100 nm in diameter and exosomes in solution is realised. Based on a statistical analysis, the mean scattering signal is related to the size of the nanoparticle. Experimentally, a mixture of nanoparticles of different diameters (200, 500, and 1000 nm) in solution is identified. To demonstrate its potential in biological applications, high-throughput counting of yeasts using a pair of microchannels and dual-wavelength detection of fluorescently labelled nanoparticles are realised. We believe that the developed nanoparticle sensor holds great potential for the multiplexed and rapid sensing of diverse viruses.
由于在基础物理和生物应用方面的重要意义，单纳米颗粒检测受到了极大的关注。在这里，我们展示了一种基于光纤的微流控传感器，用于纳米颗粒的检测和尺寸分析。得益于光纤外部的强消逝场，靠近光纤的纳米颗粒可以将部分场能散射到环境中，导致光纤传输强度降低。另一方面，狭窄而浅的微流道提供了飞升级别的检测区域，使得纳米颗粒逐个流过检测区域。通过实时监测光纤的传输强度，实现了对直径小至 100nm 的单个聚苯乙烯（PS）纳米颗粒和溶液中细胞外囊泡的检测。基于统计分析，平均散射信号与纳米颗粒的尺寸有关。在实验中，我们对溶液中不同直径（200nm、500nm 和 1000nm）的纳米颗粒混合物进行了识别。为了展示其在生物应用中的潜力，我们使用一对微通道实现了对酵母的高通量计数，并通过双波长检测实现了对荧光标记纳米颗粒的检测。我们相信，所开发的纳米颗粒传感器在多种病毒的复用和快速传感方面具有巨大的潜力。
