Phenothiazine-pyridyl chalcone: an easily accessible colorimetric and fluorimetric ‘on–off’ dual sensing probe for Cu 2+

Abstract

Phenothiazine-pyridyl chalcone, a new internal charge transfer (ICT) probe, has been designed that allows naked eye detection and a reversible, ratiometric ‘on–off’ sensing capability for biologically and environmentally significant Cu 2+ in CH 3OH–H 2O (4:1 v/v) under buffered conditions. The association constants determined using spectrophotometric and the fluorimetric techniques follow the order Cu 2+ > Ni 2+ > Co 2+ > Zn 2+ > Cd 2+ > Mg 2+ ≈ Ba 2+ ≈ Ca 2+ ≈ K +≈ Na + ≈ Li +.