Rapid Diagnostic Test for Respiratory Syncytial Virus by Digital Nanobubbles

摘要 呼吸道合胞病毒(RSV)是全球儿童死亡最常见的原因之一。快速呼吸道合胞病毒 诊断对于抗生素的司法使用、减少疾病在医疗机构中的传播以及 由于几种RSV抗病毒疗法即将问世，因此能够迅速进行治疗。当前的诊断方法 依赖耗时的实验室检测，包括病毒培养和聚合酶链式反应(PCR)，以及 快速诊断试验(如侧向流动免疫分析，LFA)不像单独诊断那样灵敏。 因此，对呼吸道合胞病毒的快速和超灵敏的诊断试验的需求尚未得到满足。等离子体激元耦合 化验是一种利用金纳米颗粒(AuNPs)的光学响应进行快速比色诊断的测试 在目标识别过程中分析其集中度。尽管它操作简单，但它的敏感性 等离子体偶联分析方法是有限的。在这项拟议的工作中，我们的目标是大幅提高以下限制 通过创新的数字纳米气泡检测(LOD)等离子体偶联分析。具体来说，我们 建议用识别RSV表面的抗体偶联AuNPs直接检测完整的RSV颗粒 融合(F)蛋白。AuNPs可与多种RSV F蛋白结合，导致胞质偶联。超短激光脉冲 与单一的AuNP相比，由于其增强的吸收，选择性地激活了偶联的AuNP。这 更大的光吸收导致纳米级的空化气泡，即纳米气泡，很容易测量 从气泡诱导的和瞬时的散射。单个纳米气泡的产生导致了敏感的数字 用“开”和“关”信号进行检测。我们的初步结果表明， 在检测呼吸道合胞病毒方面具有较高的灵敏度。在这项拟议的工作中，我们将首先通过优化AuNP来创新AuNP探针 配方(尺寸、浓度和偶联)，研究非球形纳米颗粒以获得更高的效率 病毒结合，并探索不对称抗体包裹的Janus纳米颗粒用于受控结合。下一首, 我们将设计和建造一个用于样品自动加载、读取和数据处理的原型装置 数字纳米气泡分析。最后，我们将用临床RSV分离株(来自不同的遗传毒株)来测试这一检测方法。 和临床标本。通过与现有的聚合酶链式反应和快速诊断试验的比较，建立临床应用 数字纳米气泡测试的敏感性和特异性。这种检测快速(30分钟)，成本低(AuNP试剂 成本与横向流动免疫分析相似)，对RSV具有高度的敏感性和特异性。此外，直接的 病毒颗粒的检测消除了广泛的样本准备的需要，如核酸提取。 我们项目的成功将满足快速和敏感的RSV诊断的迫切需求，并解决一个主要的 受呼吸道合胞病毒影响的儿科患者的医疗保健需求。

ABSTRACT Respiratory syncytial virus (RSV) is one of the most common causes to pediatric death globally. Rapid RSV diagnostics is important for judicial use of antibiotics, to reduce disease spread in healthcare facilities, and to enable prompt treatment since several RSV antiviral therapies are on the horizon. Current diagnostic methods rely on time-consuming laboratory-based tests including virus culture and polymerase chain reaction (PCR), and rapid diagnostic tests (e.g., lateral flow immunoassay, LFA) are not sufficiently sensitive as standalone diagnosis. Therefore, there is an unmet need for rapid and ultrasensitive diagnostic tests for RSV. The plasmonic coupling assay is a rapid colorimetric diagnostic test that makes use of the optical response of gold nanoparticles (AuNPs) during the process of target recognition to analyze its concentration. Despite its easy operation, the sensitivity of the plasmonic coupling assay is limited. In this proposed work, we aim to substantially improve the limit of detection (LOD) of the plasmonic coupling assay by innovative digital nanobubble detection. Specifically, we propose to directly detect intact RSV particles with antibody-conjugated AuNPs that recognize the RSV surface fusion (F) protein. AuNPs bind to multiple RSV F proteins and lead to plasmonic coupling. Ultrashort laser pulse selectively activates coupled AuNPs due to their enhanced absorption compared with a single AuNP. This greater optical absorption leads to nanoscale cavitation bubbles, i.e. nanobubbles, which can be measured easily from the bubble-induced and transient scattering. Single nanobubble generation leads to a sensitive digital detection with “on” and “off” signals. Our preliminary results suggest ~3 orders of magnitude improvement of LOD in detecting RSV. In this proposed work, we will firstly innovate the AuNP probe by optimizing the AuNP formulation (size, concentration and conjugation), investigating the non-spherical nanoparticle for more efficient virus binding, and exploring the asymmetric antibody-coated Janus nanoparticles for controlled binding. Next, we will design and build a prototype device for automated sample loading, reading, and data processing for the digital nanobubble assay. Lastly, we will test this assay with clinical RSV isolates (from diverse genetic strains) and clinical specimens. By comparing with current PCR and rapid diagnostic tests, we will establish the clinical sensitivity and specificity for the digital nanobubble test. This test is fast (< 30 minutes), low-cost (AuNP reagent cost is similar to lateral flow immunoassay), and highly sensitive and specific for RSV. Furthermore, the direct detection of virus particles eliminates the need of extensive sample preparation such as nucleic acid extraction. Success of our project will meet urgent demands of rapid and sensitive RSV diagnostics and address a major healthcare need for pediatric patients that are affected by RSV.