Laboratory of Biotechnology, Research Institute of Green Science and Technology, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.
Department of Applied Biological Chemistry, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan.
Biosens Bioelectron. 2017 Aug 15;94:513-522. doi: 10.1016/j.bios.2017.03.046. Epub 2017 Mar 22.
The current epidemic caused by the Zika virus (ZIKV) and the devastating effects of this virus on fetal development, which result in an increased incidence of congenital microcephaly symptoms, have prompted the World Health Organization (WHO) to declare the ZIKV a public health issue of global concern. Efficient probes that offer high detection sensitivity and specificity are urgently required to aid in the point-of-care treatment of the virus. In this study, we show that localized surface plasmon resonance (LSPR) signals from plasmonic nanoparticles (NPs) can be used to mediate the fluorescence signal from semiconductor quantum dot (Qdot) nanocrystals in a molecular beacon (MB) biosensor probe for ZIKV RNA detection. Four different plasmonic NPs functionalized with 3-mercaptopropionic acid (MPA), namely MPA-AgNPs, MPA-AuNPs, core/shell (CS) Au/AgNPs, and alloyed AuAgNPs, were synthesized and conjugated to -glutathione-capped CdSeS alloyed Qdots to form the respective LSPR-mediated fluorescence nanohybrid. The concept of the plasmonic NP-Qdot-MB biosensor involves using LSPR from the plasmonic NPs to mediate a fluorescence signal to the Qdots, triggered by the hybridization of the target ZIKV RNA with the DNA loop sequence of the MB. The extent of the fluorescence enhancement based on ZIKV RNA detection was proportional to the LSPR-mediated fluorescence signal. The limits of detection (LODs) of the nanohybrids were as follows: alloyed AuAgNP-Qdot646-MB (1.7 copies/mL)) > CS Au/AgNP-Qdot646-MB (LOD =2.4 copies/mL) > AuNP-Qdot646-MB (LOD =2.9 copies/mL) > AgNP-Qdot646-MB (LOD =7.6 copies/mL). The LSPR-mediated fluorescence signal was stronger for the bimetallic plasmonic NP-Qdots than the single metallic plasmonic NP-Qdots. The plasmonic NP-Qdot-MB biosensor probes exhibited excellent selectivity toward ZIKV RNA and could serve as potential diagnostic probes for the point-of care detection of the virus.
目前由寨卡病毒（ZIKV）引起的疫情以及该病毒对胎儿发育的破坏性影响，导致先天性小头畸形症状的发病率上升，促使世界卫生组织（WHO）宣布 ZIKV 为全球关注的公共卫生问题。迫切需要高效的探针来辅助病毒的即时治疗，这些探针应具有高检测灵敏度和特异性。在本研究中，我们展示了等离子体纳米粒子（NPs）的局域表面等离子体共振（LSPR）信号可用于介导分子信标（MB）生物传感器探针中半导体量子点（Qdot）纳米晶体的荧光信号，以检测 ZIKV RNA。合成了四种不同的巯基丙酸（MPA）功能化的等离子体 NPs，即 MPA-AgNPs、MPA-AuNPs、核/壳（CS）Au/AgNPs 和合金 AuAgNPs，并将其与 -谷胱甘肽封端的 CdSeS 合金 Qdot 缀合，形成各自的 LSPR 介导的荧光纳米杂合体。等离子体 NP-Qdot-MB 生物传感器的概念涉及使用等离子体 NPs 的 LSPR 来介导荧光信号到 Qdot，这是由目标 ZIKV RNA 与 MB 的 DNA 环序列杂交引发的。基于 ZIKV RNA 检测的荧光增强程度与 LSPR 介导的荧光信号成正比。纳米杂合体的检测限（LOD）如下：合金 AuAgNP-Qdot646-MB（1.7 拷贝/mL）> CS Au/AgNP-Qdot646-MB（LOD = 2.4 拷贝/mL）> AuNP-Qdot646-MB（LOD = 2.9 拷贝/mL）> AgNP-Qdot646-MB（LOD = 7.6 拷贝/mL）。双金属等离子体 NP-Qdot 的 LSPR 介导的荧光信号比单金属等离子体 NP-Qdot 更强。等离子体 NP-Qdot-MB 生物传感器探针对 ZIKV RNA 表现出优异的选择性，可作为用于即时检测病毒的潜在诊断探针。
