Multiresponsive Luminescent Sensitivities of a 3D Cd-CP with Visual Turn-on and Ratiometric Sensing toward Al<sup>3+</sup> and Cr<sup>3+</sup> as Well as Turn-off Sensing toward Fe<sup>3+</sup>
Yue Yu, Yuhao Wang, Hui Yan, Jing Lu, Houting Liu, Yun‐Wu Li, Suna Wang, Dacheng Li, Jianmin Dou, Lu Yang, Zhen Zhou
Abstract
By using the reduced Schiff base tricarboxylate ligand H3cip, one novel 3D Cd-based coordination polymer (Cd-CP) with the formula [Cd(Hcip)(bpea)0.5(H2O)]n (H3cip = 5-(3-carboxybenzylamino)isophthalic acid, bpea = 1,2-bis(4-pyridyl)ethane) has been solvothermally synthesized. The prepared Cd-CP possesses a 4-connected CdSO4 net based on dinuclear {Cd2} units. Luminescence measurements revealed that the complex exhibited ratiometric turn-on luminescence responses toward Al3+ and Cr3+ with a significant color change, which could be easily distinguished by the naked eye under ultraviolet light. Cd-CP can also respond to Fe3+ through a turn-off mechanism. Interestingly, the luminescence quenched by Fe3+@Cd-CP can be recovered and increased significantly by adding some competitive Al3+, while Cr3+ can only marginally increase the luminescence intensity of Fe3+@Cd-CP. Moreover, the detection of the three aforementioned metal ions can be realized by using Cd-CP-coated test papers, extending the potential application regions of the reported material to point-of-care tests and environmental field studies.