A novel sensitive aptasensor for vascular endothelial growth factor-165 (VEGF₁₆₅) was constructed based on fluorescence resonance energy transfer (FRET) by employing upconversion nanoparticles (UCNPs) and MoS₂ 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 MoS₂ nanosheets, leading to a remarkable quenching of UCNP fluorescence up to 95%. Upon addition of VEGF₁₆₅ to the UCNP–aptamer system before MoS₂ nanosheets were added, the aptamer preferentially bound to VEGF₁₆₅ with the change of spatial conformation, which weakened the van der Waals' force between the MoS₂ 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 VEGF₁₆₅ in the range of 0.1 ng mL⁻¹ to 16 ng mL⁻¹. By taking advantage of the extreme fluorescence quenching ability of MoS₂ nanosheets and the optical merits of UCNPs, the aptasensor based on UC-FRET exhibited favorable performance for the homogeneous assay of VEGF₁₆₅ in human serum, which is of great value for clinical diagnosis of tumors and related biological studies.

中文翻译：

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基于从上转换纳米粒子到MoS2纳米片的荧光共振能量转移的高度敏感的血管内皮生长因子适体传感器。

分别采用上转换纳米粒子（UCNPs）和MoS ₂纳米片作为能量供体和受体，基于荧光共振能量转移（FRET）构建了一种新型的敏感的血管内皮生长因子165（VEGF ₁₆₅）敏感适体传感器。适体和MoS ₂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），导致高达95％的UCNP荧光猝灭。在加入VEGF的₁₆₅到UCNP -适体系统的MoS之前₂中加入纳米片，适体优先结合到VEGF ₁₆₅随着空间构象的变化，削弱了MoS ₂纳米片和适体之间的范德华力，从而导致了供体和受体的分离。因此，FRET现象受到抑制，UCNPs的发光被恢复，这是线性相关的VEGF的浓度₁₆₅在0.1纳克范围毫升^-1至16纳克毫升^-1。通过利用MoS ₂纳米片的极强的荧光猝灭能力和UCNPs的光学优点，基于UC-FRET的适体传感器对VEGF ₁₆₅的均相检测显示出良好的性能。 在人血清中的含量，对肿瘤的临床诊断和相关生物学研究具有重要价值。