Hao Nanjing, Pei Zhichao, Liu Pengzhan, Bachman Hunter, Naquin Ty Downing, Zhang Peiran, Zhang Jinxin, Shen Liang, Yang Shujie, Yang Kaichun, Zhao Shuaiguo, Huang Tony Jun
Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, 27708, USA.
Small. 2020 Dec;16(48):e2005179. doi: 10.1002/smll.202005179. Epub 2020 Nov 10.
Acoustofluidics, the fusion of acoustics and microfluidic techniques, has recently seen increased research attention across multiple disciplines due in part to its capabilities in contactless, biocompatible, and precise manipulation of micro-/nano-objects. Herein, a bimodal signal amplification platform which relies on acoustofluidics-induced enrichment of nanoparticles is introduced. The dual-function biosensor can perform sensitive immunofluorescent or surface-enhanced Raman spectroscopy (SERS) detection. The platform functions by using surface acoustic waves to concentrate nanoparticles at either the center or perimeter of a glass capillary; the concentration location is adjusted simply by varying the input frequency. The immunofluorescence assay is achieved by concentrating fluorescent analytes and functionalized nanoparticles at the center of the microchannel, thereby improving the visibility of the fluorescent output. By modifying the inner wall of the glass capillary with plasmonic Ag nanoparticle-deposited ZnO nanorod arrays and focusing analytes toward the perimeter of the microchannel, SERS sensing using the same device setup is achieved. Nanosized exosomes are used as a proof-of-concept to validate the performance of the acoustofluidic bimodal biosensor. With its sample-enrichment functionality, bimodal sensing, short processing time, and minute sample consumption, the acoustofluidic chip holds great potential for the development of lab-on-a-chip based analysis systems in many real-world applications.
声流体学，即声学与微流体技术的融合，近年来在多个学科领域受到了越来越多的研究关注，部分原因在于其在非接触、生物相容性以及对微/纳米物体进行精确操控方面的能力。在此，我们介绍一种基于声流体学诱导纳米颗粒富集的双峰信号放大平台。这种双功能生物传感器能够进行灵敏的免疫荧光或表面增强拉曼光谱（SERS）检测。该平台的工作原理是利用表面声波将纳米颗粒聚集在玻璃毛细管的中心或周边；只需改变输入频率就能调整聚集位置。免疫荧光测定是通过将荧光分析物和功能化纳米颗粒聚集在微通道中心来实现的，从而提高荧光输出的可见度。通过用沉积有等离子体银纳米颗粒的氧化锌纳米棒阵列修饰玻璃毛细管内壁，并将分析物聚焦到微通道周边，利用相同的装置设置实现了SERS传感。纳米级外泌体被用作概念验证来验证声流体双峰生物传感器的性能。凭借其样品富集功能、双峰传感、短处理时间和微量样品消耗，声流体芯片在许多实际应用中为基于芯片实验室的分析系统的开发具有巨大潜力。
