Department of Mechanical Engineering, University of Texas at Dallas, Richardson, TX, 75080, USA.
Departments of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA.
Nat Commun. 2022 Mar 30;13(1):1687. doi: 10.1038/s41467-022-29025-w.
Rapid and sensitive diagnostics of infectious diseases is an urgent and unmet need as evidenced by the COVID-19 pandemic. Here, we report a strategy, based on DIgitAl plasMONic nanobubble Detection (DIAMOND), to address this need. Plasmonic nanobubbles are transient vapor bubbles generated by laser heating of plasmonic nanoparticles (NPs) and allow single-NP detection. Using gold NPs as labels and an optofluidic setup, we demonstrate that DIAMOND achieves compartment-free digital counting and works on homogeneous immunoassays without separation and amplification steps. DIAMOND allows specific detection of respiratory syncytial virus spiked in nasal swab samples and achieves a detection limit of ~100 PFU/mL (equivalent to 1 RNA copy/µL), which is competitive with digital isothermal amplification for virus detection. Therefore, DIAMOND has the advantages including one-step and single-NP detection, direct sensing of intact viruses at room temperature, and no complex liquid handling, and is a platform technology for rapid and ultrasensitive diagnostics.
快速、灵敏的传染病诊断是当务之急，但目前仍未得到满足，COVID-19 大流行就证明了这一点。在这里，我们报告了一种基于数字等离子体纳米泡检测（DIAMOND）的策略来满足这一需求。等离子体纳米泡是等离子体纳米粒子（NPs）激光加热产生的瞬态蒸汽泡，允许对单个 NP 进行检测。我们使用金 NPs 作为标记物和光流控装置，证明 DIAMOND 可实现无间隔的数字计数，并可在无需分离和扩增步骤的均相免疫测定中工作。DIAMOND 可特异性检测鼻腔拭子样本中添加的呼吸道合胞病毒，检测限约为 100 PFU/mL（相当于 1 RNA 拷贝/µL），与病毒检测的数字等温扩增相当。因此，DIAMOND 具有一步和单 NP 检测、在室温下直接检测完整病毒以及无需复杂的液体处理等优势，是一种用于快速、超灵敏诊断的平台技术。
