A Selenamorpholine and Pyrimidine-based Redox-responsive Fluorescent Probe and Its Response Mechanism

Abstract A new type of hydrogen peroxide (H2O2) fluorescent probe Pyrimidine-Se was synthesized from selenomorpholine and pyrimidinyl and the large Stokes shift (Δλ>140 nm) was exhibited. The fluorescence intensity of Pyrimidine-Se is very sensitive to pH, and its pKa value is 9.06. While the probe is reacted with H2O2, the selenomorpholine changes from Se (II) to Se (IV), which enhances the electron-withdrawing ability of the Pyrimidine-Se electron-withdrawing group. Based on this, the probe Pyrimidine-Se was used to detect H2O2 by the fluorescence spectrum. The detection limit of the probe Pyrimidine-Se was 1.3 µM. At the same time, we also found that Pyrimidine-Se displayed the reversibility back and forth between H2O2 and GSH. The reaction mechanism with H2O2 was verified by mass spectrometry and simulation on the Gaussian 09 program.