Novel in situ-generated highly fluorescent chelated Zn2+–anthracene (Zn2+•P: 1:1) complex detected 2,4,6-trinitrophenol (TNP) more selectively by a “switch-off” response with a very high Stern–Volmer quenching constant (Ksv = 3.75 × 106 M−1) at a 1:2 stoichiometry in 80% aqueous DMSO. The selective quenching response that occurred with TNP is due to the effective destruction of the chelated complex by efficient protonation at secondary amines, which created an effective resonance energy transfer (RET) from the anthracene unit to the TNP. Formation of a stable P2+•(TNP)−2 ionic charge-transfer complex showed that the anthracene monomer band quenching resulted from efficient RET, accompanied by synergistic multiple hydrogen bonding, electron-rich–electron-deficient πAn–πTNP interactions, and columbic interactions. An application was demonstrated using the biocompatible ensemble-coated hydrogel for ultraviolet-assisted naked eye sensing, and its sensing mechanism was postulated. The lowest detection limit for TNP was 3.01 × 10−10 M in 80% aqueous DMSO.
ASJC Scopus subject areas
- 化學 (全部)