An unsaturated monomer bearing luminescence group

acryloyloxyfluorescein (Ac-Flu) was synthesized from fluorescein and acryloyl chloride in the presence of triethylamine in dry dichloromethane (CH2Cl2) at room temperature.The synthesized Ac-Flu was identified by IR

MS and 1H-NMR spectra.Copolymer of Ac-Flu and acrylamide was synthesized with thermal initiator

and poly(Ac-Flu-co-AM) was characterized by the method of IR

UV-Vis and DSC.The photophysical behaviors of the copolymer were explored by recording the fluorescence spectra in solution and film.In addition

the pH and temperature dependence of fluorescence of the water-soluble poly(Ac-Flu-co-AM) was investigated in detail.The results showed that the relative fluorescence intensity of poly(Ac-Flu-co-AM) at near 520 nm had an excellent linear response to temperature in the range of 0~60℃

the linear regression equation of the calibration graph was FI=740.06-3.0683T

(FI was relative fluorescence intensity

T was temperature)

with a correlation coefficient of linear regression of 0.9974.Moreover

the fluorescence intensity increased continuously from low pH to high pH from 4.0 to 10.0 after the addition of HCl or NaOH

which resulted from the fact that the predominance of tautomeric forms of Ac-Flu changed at different medium.This investigation may provide a convenient way to prepare multifunctional macromolecule biomaterial bearing fluorescein to probe pH and temperature in biological system.