A chromogenic diarylethene-based probe for the detection of Cu in aqueous medium in for early diagnosis of Alzheimer.

A diarylethene-based probe ( has been proficiently developed and its structure has been confirmed by single crystal X-ray diffraction technique. It displays a selective and sensitive colorimetric sensing of Cu ions in aqueous medium with a naked eye colour change from colourless to yellow. It exhibits a significantly low limit of detection as 1.5 nM. A plausible binding mechanism has been proposed using Job's plot, FT-IR, H NMR titration, HRMS and DFT studies. The chemosensor is effectively reversible and reusable with EDTA. Test strip kit and real water sample analysis have been shown to establish its practical applicability. Further, the potential of for the early diagnosis of Cu ion-induced amyloid toxicity has been investigated in eye imaginal disc of Alzheimer's disease model of 3rd instar larvae. The in-vivo interaction of with Cu in gut tissues of larvae establishes its sensing capability in biological system. Interestingly, the in-vivo detection of Cu has been done using bright field imaging which eliminates the necessity of a fluorescent label, hence making the method highly economical.