Zhang, Ru, Yu, Junhui, Chen, Haiou, Zhou, Yu, Yang, Xiangjun, Wang, Shixiong, and Bai, Huiping
Flower-like TpTa-COF was synthesized by the one-step solvothermal method, and a novel electrochemical platform for separation and simultaneous sensitive detection of trace Pb(II) and Cd(II) in surface water was constructed based on TpTa-COF. The proposed sensor has the advantages of low detection limit, high sensitivity, and good stability, and has been successfully applied to the determination of Pb (II) and Cd(II) in two actual water samples. [Display omitted] • Flower-like TpTa-COF was synthesized by the simple solvent method for the first time. • TpTa-COF can provide abundant active sites for trace detection of Pb(II) and Cd(II). • The sensor exhibited a wide detection range and low detection limit. • The detection mechanism of TpTa-COF was explored through XPS and simulation calculation. Heavy metal pollution in aquatic environment poses an enormous risk to ecosystems and human health. In this study, a flowerlike covalent organic framework (TpTa-COF) was synthesized by one-step solvothermal method with 2,4,6-triformylphloroglucinol (Tp) and 4, 4-diamino-tribiphenyl (Ta) as building elements. Then it was used as an effective trap to establish an electrochemical sensing platform for simultaneously sensitive detection of trace Pb(II) and Cd(II) in water. This three-dimensional flower-shaped structure exhibited exceptional adsorption capacity, large surface area, high stability, and all of which enhanced the detection sensitivity of the sensor and facilitated full contact between ions and substrate. The high oxygen content in the structure provided abundant active sites for Pb(II) and Cd(II), further enhancing its electrochemical response. The constructed sensor exhibited a linear response to Pb(II) within the concentration range of 3–60 µg/L under the optimal conditions, with a detection limit of 0.16 µg/L. Similarly, a linear response was observed for Cd(II) in the concentration range of 5–60 µg/L, with a detection limit of 0.29 µg/L. Low detection limits, excellent sensitivity, and strong stability were all features of the suggested approach. It has been successfully employed in determining Pb(II) and Cd(II) concentrations in two actual water samples. XPS, SEM-EDS mapping, and density functional theory calculations confirmed that TpTa-COF interacted with metal ions mainly via coordination with carbonyl oxygen atoms in the structure. Overall, these findings will broaden the applications of COF in the field of chemical analysis. [ABSTRACT FROM AUTHOR]