Herein, we introduce a novel, ultrasensitive optical sensor for determination of Cu(II) ions over the concentration range of 0 to 1 μM Cu(II). The optical sensor is based on the natural molecule chrysosplenol-D (Chp-D) extracted from the flowering plant Chiliadenus montanus (Vahl.) Brullo. Free Chp-D emits fluorescence at 566 nm when excited at 292 nm. Chp-D chelates Cu(II) ions to form a 1:1 (metal:ligand) complex, which quenches the fluorescence emission peak of the free probe at 566 nm. “Turn-off” luminescence could be easily determined and provided distinct proof of the chelation of Cu(II) ions by Chp-D. This novel optical sensor offers a considerable fluorescence mechanism (charge transfer complex, CTC). Chp-D is an extremely sensitive and selective optical sensor for Cu(II) ions, with distinctive fluorescence properties, a large Stokes shift of ~275 nm and recognition aptitude. Moreover, Chp-D has low limit of detection (LOD) for Cu(II) of 1.2 × 10⁻⁸ M in buffered media at physiological pH (pH 7.4), a linear range of 0.04 to 1.0 μM and a relative standard deviation (RSD_r) of 1% (n = 3). Furthermore, this natural probe has a high binding affinity for Cu(II), with a binding constant of 3.36 × 10⁸ M⁻¹. Overall, we propose Chp-D represents a novel, natural optical sensor for the detection of Cu(II).

在这里，我们介绍了一种新颖的超灵敏光学传感器，用于测定浓度范围为0至1μMCu（II）的Cu（II）离子。光学传感器基于从开花植物Chiliadenus montanus提取的天然分子chrysosplenol-D（Chp-D）（瓦赫尔）布鲁洛。当在292 nm处激发时，游离Chp-D会在566 nm处发出荧光。Chp-D螯合Cu（II）离子形成1：1（金属：配体）络合物，该络合物在566 nm处淬灭了游离探针的荧光发射峰。可以很容易地确定“关闭”发光，并提供了Chp-D与Cu（II）离子螯合的独特证据。这种新颖的光学传感器提供了相当大的荧光机制（电荷转移复合物，CTC）。Chp-D是一种对Cu（II）离子极为敏感和选择性的光学传感器，具有独特的荧光特性，约275 nm的大斯托克斯位移和识别能力。此外，Chp-D 在生理pH（pH 7.4）的缓冲液中对Cu（II）的检测限（LOD）为1.2×10 ^-8 M，线性范围为0.04至1.0μM，相对标准偏差为（ RSD_r）为1％（n  = 3）。此外，该天然探针对Cu（II）具有高结合亲和力，结合常数为3.36×10 ⁸  M ^-1。总体而言，我们建议Chp-D代表一种新颖的天然光学传感器，用于检测Cu（II）。