It is of great significance to sensitively and selectively detect uranyl ion (UO₂²⁺) in environmental and biological samples due to the high risks of UO₂²⁺ to human health. However, such suitable sensors are still scarce. A novel fluorescence sensor based on a dansyl-modified peptide, Dansyl-Glu-Glu-Pro-Glu-Trp-COOH (D-P5), was efficiently synthesized by Fmoc solid phase peptide synthesis. As the first linear peptide-based fluorescence sensor for UO₂²⁺, D-P5 exhibited high selectivity and sensitivity to UO₂²⁺ over 27 metal ions (UO₂²⁺, Cr³⁺, Cu²⁺, Ba²⁺, Hg²⁺, Pb²⁺, Co²⁺, Ag⁺, Fe³⁺, Ca²⁺, K⁺, Mg²⁺, Mn²⁺, Na⁺, Ni²⁺, Cd²⁺, Zn²⁺, Al³⁺, Dy³⁺, Er³⁺, Gd²⁺, Ho³⁺, La³⁺, Lu³⁺, Pr³⁺, Sm³⁺, Tm³⁺) by a turn-off fluorescence response in 10 mM HEPES buffer (pH 6.3). The effects of anions such as S²⁻, NO₃^–, SO₄²⁻ CO₃^2–, HCOO^–, antioxidant ascorbic acid and 4-nitrophenyl acetate on the selectivity for UO₂²⁺ detection were also studies. D-P5 sensor could be used for detecting UO₂²⁺ in a good linear relationship with concentration in the range of 0–8.0 μM with a low limit of detection of 83.2 nM. Furthermore, the interaction of the sensor with UO₂²⁺ was characterized by ESI-MS, IR, XPS and ITC measurements. The 1:1 binding stoichiometry between the sensor and UO₂²⁺ was measured by the job’s plot and further verified by ESI-MS. The binding constant of the sensor with UO₂²⁺ was calculated to be 9.8 × 10⁴ M⁻¹ by modified Benesi-Hildebrand equation. ITC results showed that theΔH^θ andΔS^θ for the interaction of D-P5 with UO₂²⁺ were −(7.167 ± 1.25) kJ·mol⁻¹ and 66.5 J·mol⁻¹·K⁻¹, respectively. Time-resolved fluorescence spectroscopy indicated that the mechanism of fluorescence quenching of D-P5 by UO₂²⁺ ion was static quenching process. In addition, this sensor displayed a good practicality for UO₂²⁺ detection in lake water sample without tedious sample pretreatment.

_{由于UO 2} ²⁺对人体健康的高风险，灵敏、选择性地检测环境和生物样品中的铀酰离子(UO 2 2+ )_具有^重要意义。然而，这样合适的传感器仍然很少。通过 Fmoc 固相肽合成，高效合成了一种基于丹酰修饰肽 Dansyl-Glu-Glu-Pro-Glu-Trp-COOH (D-P5) 的新型荧光传感器。作为第一个基于线性肽的 UO ₂ ²⁺荧光传感器，D-P5 对 UO ₂ ²⁺超过 27 种金属离子（UO ₂ ²⁺、Cr ³⁺、Cu ²⁺、Ba ²⁺、汞²⁺ , Pb ²⁺ , Co ²⁺ , Ag ⁺ , Fe ³⁺ , Ca ²⁺ , K ⁺ , Mg ²⁺ , Mn ²⁺ , Na ⁺ , Ni ²⁺ , Cd ²⁺ , Zn ²⁺ , Al ^{3 +} , Dy ³⁺ , Er ³⁺ , Gd ²⁺ , Ho ³⁺ , La ³⁺ , Lu ³⁺ , Pr ³⁺ , Sm ³⁺ , Tm ³⁺ ) 通过在 10 mM HEPES 缓冲液中的关闭荧光响应（pH 值 6.3）。^{S 2−}等阴离子的作用, NO ₃ ^– , SO ₄ ²⁻ CO ₃ ^2– , HCOO ^– , 抗氧化剂抗坏血酸和乙酸4-硝基苯酯对UO ₂ ²⁺检测选择性的影响也进行了研究。D-P5传感器可用于检测UO ₂ ²⁺，浓度在0-8.0 μM范围内呈良好的线性关系，检测下限为83.2 nM。此外，传感器与 UO ₂ ²⁺的相互作用通过 ESI-MS、IR、XPS 和 ITC 测量来表征。传感器与UO ₂ ^{2+的1:1结合化学计量}由工作图测量并由 ESI-MS 进一步验证。传感器与UO ₂ ²⁺的结合常数通过修正的Benesi-Hildebrand 方程计算为9.8 × 10 ⁴ M ^{−1 。}ITC 结果表明， D-P5 与UO ₂ ²⁺相互作用的ΔH ^θ和ΔS ^θ分别为-(7.167 ± 1.25) kJ·mol ^-1和66.5 J·mol ^-1 ·K ^-1。_{时间分辨荧光光谱表明UO 2} ²⁺对D-P5荧光猝灭的机理离子呈静电淬火过程。此外，该传感器在无需繁琐的样品预处理的情况下，对湖水样品中的UO ₂ ^{2+检测显示出良好的实用性。}