Yrad Flora M, Castañares Josephine M, Alocilja Evangelyn C
Nano-Biosensors Lab, Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing, MI 48824, USA.
Department of Chemistry, University of San Carlos, Talamban, Cebu 6000, Philippines.
Diagnostics (Basel). 2019 Jul 11;9(3):74. doi: 10.3390/diagnostics9030074.
Dengue is a rapidly spreading mosquito-borne viral disease. Early diagnosis is important for clinical screening, medical management, and disease surveillance. The objective of this study was to develop a colorimetric lateral flow biosensor (LFB) for the visual detection of dengue-1 RNA using dextrin-capped gold nanoparticle (AuNP) as label. The detection was based on nucleic acid sandwich-type hybridization among AuNP-labeled DNA reporter probe, dengue-1 target RNA, and dengue-1 specific DNA capture probe immobilized on the nitrocellulose membrane. Positive test generated a red test line on the LFB strip, which enabled visual detection. The optimized biosensor has a cut-off value of 0.01 µM using synthetic dengue-1 target. Proof-of-concept application of the biosensor detected dengue-1 virus in pooled human sera with a cut-off value of 1.2 × 10 pfu/mL. The extracted viral RNA, when coupled with nucleic acid sequence-based amplification (NASBA), was detected on the LFB in 20 min. This study first demonstrates the applicability of dextrin-capped AuNP as label for lateral flow assay. The biosensor being developed provides a promising diagnostic platform for early detection of dengue infection in high-risk resource-limited areas.
登革热是一种迅速传播的蚊媒病毒性疾病。早期诊断对于临床筛查、医疗管理和疾病监测至关重要。本研究的目的是开发一种比色侧向流动生物传感器（LFB），用于以糊精包被的金纳米颗粒（AuNP）作为标记物对登革热1型RNA进行可视化检测。检测基于AuNP标记的DNA报告探针、登革热1型靶RNA和固定在硝酸纤维素膜上的登革热1型特异性DNA捕获探针之间的核酸夹心型杂交。阳性检测在LFB条带上产生红色检测线，从而实现可视化检测。使用合成的登革热1型靶标，优化后的生物传感器的截断值为0.01 µM。该生物传感器的概念验证应用在人混合血清中检测登革热1型病毒，截断值为1.2×10 pfu/mL。提取的病毒RNA与基于核酸序列的扩增（NASBA）结合后，在20分钟内可在LFB上检测到。本研究首次证明了糊精包被的AuNP作为侧向流动分析标记物的适用性。正在开发的生物传感器为在高风险资源有限地区早期检测登革热感染提供了一个有前景的诊断平台。
