A chemodosimeter for selective fluorogenic and chromogenic detection of phenylenediamine isomers.

A chromogenic and fluorogenic active coumarin-based chemodosimeter (DP21) has been synthesized. The probe shows remarkable fluorescent intensity with phenylenediamine isomers (PDA) such as ortho-phenylenediamine (OPD) and para-phenylenediamine (PPD) in the presence of competitive species. The probe changes from light yellow to reddish brown and dark yellow with OPD and PPD, respectively, through naked eye. The interaction of lone pair electrons in carbonyl group present in DP21 with amino group of OPD and PPD shows the intermolecular hydrogen bonding. The PDA isomers can be detected selectively in the presence of other interfering organic and inorganic amines by the DP21. It shows excellent low detection limit (LOD) for OPD and PPD is 0.19 nM and 0.4 nM respectively. [ABSTRACT FROM AUTHOR]