Two novel dyes containing spirobifluorene and triphenylamine: Synthesis, one- and two-photon excited fluorescence and applications as probes for silver ions, water and cell imaging

Two fluorophores, SPF-TNS and SPF-TBB, with electron-rich triphenylamine groups and Ag+ receptor units on the respective biphenyl branches of 9,9'-spirobifluorene were synthesized. They exhibit strong one- and two-photon excited fluorescence, and the two-photon absorption cross-section values are 665 GM for SPF-TNS and 355GM for SPF-TBB. The probing behaviors toward metal ions were investigated via UVIVis absorption spectra as well as one-photon fluorescence changes. The results indicated that SPF-TNS and SPF-TBB exhibit distinct fluorescent quenching in the presence of silver ions that can be used for highly sensitive and selective naked-eye detection of Ag+ The one-photon excited fluorescence of SPF-TBB can be made to measure water content of organic solvents. The detection limits were calculated to be 0.04% for THE and 0.03% for 1,4-dioxane. The two-photon scanning microscopy experiments suggest that SPF-TNS is a promising label potentially applicable for the tracking of biomolecules. (C) 2016 Elsevier B.V. All rights reserved.