Silver nanoparticles-enhanced time-resolved fluorescence sensor for VEGF(165) based on Mn-doped ZnS quantum dots.
Silver nanoparticles-enhanced time-resolved fluorescence sensor for VEGF(165) based on Mn-doped ZnS quantum dots.
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DOI：
10.1016/j.bios.2015.08.005
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发表时间：
2015-12
影响因子：
12.6
通讯作者：
Dong Zhu;Wei Li;H. Wen;Sheng Yu;Z. Miao;An Kang;Aihua Zhang
中科院分区：
文献类型：
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作者：
Dong Zhu;Wei Li;H. Wen;Sheng Yu;Z. Miao;An Kang;Aihua Zhang
建立了一种基于Mn掺杂ZnS量子点的银纳米颗粒增强时间分辨荧光（TR-FL）传感器，用于检测肿瘤血管生成的主要生物标志物血管内皮生长因子165（VEGF 165）。与Mn掺杂的ZnS量子点和BHQ-2猝灭剂标记链结合的适配体与链霉亲和素（SA）官能化的AgNP偶联以形成AgNP增强的TR-FL传感器，由于Mn掺杂的ZnS量子点和猝灭剂之间的荧光共振能量转移（FRET），在双链体状态下显示出较低的荧光强度。加入VEGF 165后，双链体的BHQ-2猝灭剂标记链被置换，导致FRET破坏。结果，AgNP附近的Mn掺杂的QD的荧光被恢复。通过设置适当的延迟时间和选通时间，可以使荧光信号不受短寿命背景的干扰，从而为荧光生物检测提供高信噪比的信号。与裸TR-FL传感器相比，基于AgNPs的TR-FL传感器显示出基于金属增强荧光（MEF）效应的荧光的巨大改善，并且灵敏度提高了11倍，检测限为0.08 nM。此外，该传感器提供了从0.1 nM到16 nM的宽范围的线性检测。
A silver nanoparticles (AgNPs)-enhanced time-resolved fluorescence (TR-FL) sensor based on long-lived fluorescent Mn-doped ZnS quantum dots (QDs) is developed for the sensitive detection of vascular endothelial growth factor-165 (VEGF165), a predominant cancer biomarker in cancer angiogenesis. The aptamers bond with the Mn-doped ZnS QDs and the BHQ-2 quencher-labelling strands hybridized in duplex are coupled with streptavidin (SA)-functionalized AgNPs to form the AgNPs-enhanced TR-FL sensor, showing lower fluorescence intensity in the duplex state due to the fluorescence resonance energy transfer (FRET) between the Mn-doped ZnS QDs and quenchers. Upon the addition of VEGF165, the BHQ-2 quencher-labelling strands of the duplex are displaced, leading to the disruption of the FRET. As a result, the fluorescence of the Mn-doped QDs within the proximity of the AgNPs is recovered. The FL signal can be measured free of the interference of short-lived background by setting appropriate delay time and gate time, which offers a signal with high signal-to-noise ratio in photoluminescent biodetection. Compared with the bare TR-FL sensor, the AgNPs-based TR-FL sensor showed a huge improvement in fluorescence based on metal-enhanced fluorescence (MEF) effect, and the sensitivity increased 11-fold with the detection limit of 0.08 nM. In addition, the sensor provided a wide range of linear detection from 0.1 nM to 16 nM.