Whispering Gallery Mode Carousel: A means for Enhanced Detection in Biosensing and Surface-Force Probing

回音壁模式旋转木马：生物传感和表面力探测中增强检测的方法

• 批准号: 0933531
• 负责人: Stephen Arnold
• 金额: --
• 依托单位: Polytechnic University of New York
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0933531&HistoricalAwards=false
• 关键词: Whispering; Gallery; Mode; Carousel; means

0933531ArnoldVirus particles are a major cause for human disease, and their early detection and identification is of increasing importance as air travel allows these infectious agents to spread rapidly to populations across the globe. A fast detector that is sensitive to a single virus particle by determining its genus and size would answer the demand for early detection. The present proposal is to continues the investigation into microsphere whispering gallery mode (WGM) biosensors for early detection of viruses in human fluids as we utilize a recently discovered phenomenon of light trapping of nanoparticles within the WGM evanescent volume. The sensing is based on the extremely narrow photonic resonances of microspheres that shift their frequencies as a result of an environmental change. Within the reach of the WGM?s evanescent field (~ 200 nm) nanoparticles are drawn toward the surface by gradient forces, similar to those present in optical tweezers. A trapping potential-well is formed by an attractive evanescent polarization potential, repulsive electrostatic potential, and van der Waals potential. In the case of a low binding-affinity or a low density of binding sites, nanoparticles are propelled around in orbit by radiation pressure. This trapping mechanism (WGM Carousel) along with controlled binding-affinity adds additional functionality and assures high sensitivity and specificity to the WGM biosensor. The ultimate goal is to build microfluidic biosensors that are sensitive to a single viral particle and can differentiate virions according to their size/mass and affinity to specific antibodies. The small size of these bio-particles demands micrometer-size sensors3. However Brownian diffusion of ultra-low concentration analytes crossing the boundary layer is considered a major hurdle4 for miniature sensors. Preliminary results show that the WGM Carousel sensor can have significantly enhanced transport rates ( 50×) of particles to the sensing region, compared to other miniature sensors. In addition the carousel mechanism provides a means for investigating forces arising near the surface. Understanding these forces is of great importance for the design of microfluidic devices and micro-fabrication. Nanoparticles trapped in a WGM carousel can be used to quantitatively measure surface interactions from their stochastic radial motion. By proper choice of the interacting surfaces and the liquid medium it will be possible to screen the electrostatic repulsion and reveal short range interactions such as van der Waals. There are challenges for the DLVO (the theory of colloidal stability) to properly describe the interactions at very short range (5nm) for various aqueous solutions, where repulsive solvation forces are observed. WGM Carousel will help address these challenges.

0933531Arnoldvirus颗粒是人类疾病的主要原因，由于空中旅行允许这些传染性药物能够迅速扩散到全球种群，因此它们的早期检测和鉴定具有越来越重要的重要性。通过确定其属和大小对单个病毒颗粒敏感的快速检测器将回答早期检测的需求。目前的建议是继续研究微球窃窃库模式（WGM）生物传感器，以早日检测到人类液体中的病毒，因为我们利用了最近发现的WGM中纳米颗粒的光捕获现象。感应是基于微球的极狭窄的光子共振，由于环境变化而改变了它们的频率。在WGM的触及范围内（〜200 nm）纳米颗粒被梯度力朝向表面，类似于光学镊子中的纳米颗粒。诱捕电孔由有吸引力的爆炸性偏振电位，排斥性静电电势和范德华电位形成。在低结合 - 亲属或低密度结合位点的情况下，纳米颗粒会通过辐射压力在轨道上推动。这种捕获机制（WGM旋转木制）以及受控的结合 - 亲属增加了其他功能，并确保对WGM生物传感器的高灵敏度和特异性。最终目标是构建对单个病毒颗粒敏感的微流体生物传感器，并可以根据病毒的大小/质量和对特定抗体的亲和力来区分病毒。这些生物颗粒的小尺寸需要微米大小的传感器3。然而，越过边界层的超低浓度分析物的布朗差异被认为是微型传感器的主要栏4。初步结果表明，与其他微型传感器相比，WGM旋转木马传感器可以显着提高到感觉区域的传输速率（50×）颗粒。此外，轮播机制提供了一种调查在表面附近产生的力的手段。理解这些力对于设计微流体设备和微型制作至关重要。被困在WGM旋转木马中的纳米颗粒可用于从其随机径向运动中定量测量表面相互作用。通过正确选择相互作用的表面和液体培养基，可以筛选静电排斥并揭示诸如范德华等短范围相互作用。 DLVO（胶体稳定性理论）的挑战是正确描述各种水溶液在非常短范围（5nm）的相互作用，在这些溶液中观察到排斥溶液。 WGM旋转木马将有助于应对这些挑战。