A Sensitive Probe of Meso -Cyanophenyl Substituted BODIPY Derivative as Fluorescent Chemosensor for the Detection of Multiple Heavy Metal Ions

A fluorescent turn-on chemosensor ( BA ) was constructed by attaching bis(pyridin-2-ylmethyl)-amine (DPA) unit to the BODIPY scaffold. It can give a prominent green/yellow fluorescent response selectivity with each of Zn 2+ /Hg 2+ /Cd 2+ /Ca 2+ /Mn 2+ /Pb 2+ /Al 3+ . The 1:1 stoichiometry of BA and metal ions was drawn from the analysis of Job’s plot. The limit detection of BA in recognition of Zn 2+ /Hg 2+ /Cd 2+ /Ca 2+ /Mn 2+ /Pb 2+ /Al 3+ is ranged in 50.8-146.6 nM. There exists a linear relationship between the fluorescence intensity and concentration of metal ions (Zn 2+ : 4-15 µM). The mechanism of fluorescence signal “turn-on” is based on the photo induced transfer (PET) in the excited state of BA . The coordinated metal ions significantly weakened the electron-donating ability nitrogen atom in DPA, thus recovering the emission character of BODIPY. The substituted group at the phenyl ring in meso -position of BODIPY scaffold determines the recognizable list of metal ions.