The preparation and photophysical behaviors of temperature/pH-sensitive polymer materials bearing fluorescein

Abstract A novel method for attaching fluorescein (via its epoxy derivate) to water soluble polymer and its temperature/pH-sensitive qualities of fluorescence were investigated. 3-Epoxypropoxy fluorescein (EPF) was firstly synthesized through the reaction between fluorescein and epichlorohydrin and poly (vinyl alcohol) bearing fluorescein was prepared via ring-opening reaction with EPF. Both of them were characterized by the methods of HNMR, MS, IR, UV–Vis, DSC and fluorescence spectra, respectively. The chemiluminescent and photophysical behaviors of the dye fluorescein derivative and the polymer-containing fluorescein had been studied, and the ability of film forming of PVA–EPF and the effect of different solvents on its fluorescence behavior were reported in this article. In addition, the pH and temperature dependences of fluorescence of PVA–EPF were investigated in detail. All those observations suggested that the PVA–EPF was an excellent luminescent macromolecular material with a convenience method for the preparation and an excellent water-soluble ability. Moreover its pH and temperature sensitivities of the fluorescence can be advantageous for it to become a multifunctional material to probe pH and temperature.