Yuan Yunxia, Yu Huichun, Yin Yong
College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471023, China.
Anal Methods. 2020 Sep 28;12(36):4466-4472. doi: 10.1039/d0ay01067g. Epub 2020 Aug 28.
A novel sensitive aptasensor for vascular endothelial growth factor-165 (VEGF) was constructed based on fluorescence resonance energy transfer (FRET) by employing upconversion nanoparticles (UCNPs) and MoS nanosheets as the energy donor and acceptor, respectively. The upconversion fluorescence resonance energy transfer (UC-FRET) was triggered by the physical adsorption interaction between the aptamer and MoS nanosheets, leading to a remarkable quenching of UCNP fluorescence up to 95%. Upon addition of VEGF to the UCNP-aptamer system before MoS nanosheets were added, the aptamer preferentially bound to VEGF with the change of spatial conformation, which weakened the van der Waals' force between the MoS nanosheets and the aptamer, thus leading to the separation of the donor and the acceptor. Consequently, the FRET phenomenon was inhibited and the luminescence of UCNPs was regained, which was linearly related to the concentration of VEGF in the range of 0.1 ng mL to 16 ng mL. By taking advantage of the extreme fluorescence quenching ability of MoS nanosheets and the optical merits of UCNPs, the aptasensor based on UC-FRET exhibited favorable performance for the homogeneous assay of VEGF in human serum, which is of great value for clinical diagnosis of tumors and related biological studies.
基于荧光共振能量转移（FRET）构建了一种新型的用于检测血管内皮生长因子-165（VEGF）的灵敏适体传感器，分别以上转换纳米颗粒（UCNPs）和MoS纳米片作为能量供体和受体。适体与MoS纳米片之间的物理吸附相互作用触发了上转换荧光共振能量转移（UC-FRET），导致UCNP荧光显著猝灭，猝灭率高达95%。在加入MoS纳米片之前向UCNP-适体体系中添加VEGF时，适体优先与VEGF结合，空间构象发生变化，这削弱了MoS纳米片与适体之间的范德华力，从而导致供体和受体分离。因此，FRET现象受到抑制，UCNPs的发光得以恢复，其在0.1 ng/mL至16 ng/mL范围内与VEGF浓度呈线性关系。利用MoS纳米片的极端荧光猝灭能力和UCNPs的光学优点，基于UC-FRET的适体传感器在人血清中VEGF的均相检测中表现出良好的性能，这对肿瘤的临床诊断和相关生物学研究具有重要价值。
