Highly selective detection of copper(II) by a “ligand-free” conjugated copolymer in nucleophilic solvents


The synthesis of N-cyclohexyl carbamate-attached fluorene-alt-phenylene copolymer (PFPNCC) and the use of PFPNCC as a “ligand-free” fluorescent chemosensor for Cu(II) are described. Addition of Cu(II) can efficiently quench the fluorescence of PFPNCC in nucleophilic solvents such as DMF and DMSO, but not in low nucleophilic solvents such as 1,4-dioxane and THF. Ultraviolet-visible spectra of the mixture of the conjugated polymer and Cu(II) indicate the presence of a reduced Cu (I) ion in the solution. Furthermore, fluorescence recovery of PFPNCC observed at low temperature suggests that the quenching and reducing mechanism is most probably due to a photo-induced electron transfer from excited PFPNCC to Cu(II). Our findings provide a novel strategy for highly selective conjugated polymer-based chemosensors for various target analytes, albeit “ligand-free”.

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This work was financially supported by the National Basic Research Program of China (Grant No. 2015CB932200), the National Natural Science Foundation of China (Grant Nos. 21604042, 61378081, 21574064, and 21674048), Synergetic Innovation Center for Organic Electronics and Information Displays, Jiangsu National Synergetic Innovation Center for Advanced Materials, the Natural Science Foundation of Jiangsu Province of China (No. BK20150843), NUPTSF (Nos. NY215017, NY211003, and NY215080) and the Innovation Program for Postgraduates Research of Colleges and Universities of Jiangsu Province (No. CXZZ12-0459).

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Correspondence to Quli Fan or Tsuyoshi Minami.

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Deng, W., Sun, P., Fan, Q. et al. Highly selective detection of copper(II) by a “ligand-free” conjugated copolymer in nucleophilic solvents. Front. Chem. Sci. Eng. 14, 105–111 (2020). https://doi.org/10.1007/s11705-019-1791-6

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  • ligand-free
  • fluorescent chemosensor
  • copper
  • photo-induced electron transfer