Department of Chemistry, K. N. Toosi University of Technology, P.O. Box 15875-4416, Tehran, Iran.
University of Hamburg, Martin-Luther-King Platz 6, 20146, Hamburg, Germany.
Anal Bioanal Chem. 2021 Jun;413(15):3881-3891. doi: 10.1007/s00216-021-03339-y. Epub 2021 Apr 30.
Two novel fluorescent peptide-based chemosensors, including A (2-amino-benzoyl-Ser-Glu-Glu-NH) and B (2-amino-benzoyl-Ala-Glu-Pro-Glu-Ala-Glu-Pro-NH) were synthesized and characterized by nuclear magnetic resonance (NMR) spectra. These fluorescent probes exhibited excellent selective and sensitive responses to Al ions over other metal ions in aqueous buffered solutions. The limits of detection for both chemosensors towards the Al ions were in the order of ∼10 M (A: 155 nM and B: 195 nM), which clearly indicates that these probes have significant potential for biological applications. They also displayed high binding affinity (1.3029 × 10 M and 1.7586 × 10 M relevant to A and B respectively). These two chemosensors are great analytical probes that produce turn-on responses upon binding to Al ions through an intramolecular charge transfer (ICT) mechanism. In addition, the application of both chemosensors was examined over a wide range of pH. The fluorescent peptide-based probes and Al form a 1:1 coordination complex according to the ESI-MS and Job's plot analysis. Notably, upon addition of Al to these chemosensors, a fluorescence enhancement of approximately 8-fold was observed and the binding mode was determined using NMR titration and fluorescence emission data.
两种新型基于荧光肽的化学传感器，包括 A（2-氨基苯甲酰-Ser-Glu-Glu-NH）和 B（2-氨基苯甲酰-Ala-Glu-Pro-Glu-Ala-Glu-Pro-NH），通过核磁共振（NMR）谱进行了合成和表征。这些荧光探针在水缓冲溶液中对 Al 离子具有优异的选择性和敏感性响应，优于其他金属离子。两种化学传感器对 Al 离子的检测限均在 10^-7 M 左右（A：155 nM 和 B：195 nM），这表明这些探针具有显著的生物学应用潜力。它们还显示出高的结合亲和力（A 和 B 分别为 1.3029×10^4 M 和 1.7586×10^4 M）。这两种化学传感器都是通过分子内电荷转移（ICT）机制与 Al 离子结合产生开环响应的出色分析探针。此外，还对两种化学传感器在较宽 pH 范围内的应用进行了研究。根据 ESI-MS 和 Job's 图谱分析，荧光肽基探针和 Al 形成 1:1 的配位络合物。值得注意的是，向这些化学传感器中加入 Al 后，观察到荧光增强约 8 倍，并通过 NMR 滴定和荧光发射数据确定了结合模式。
