A versatile rhodamine B-derived fluorescent probe for selective copper(II) sensing

Abstract

In the current study, a colourimetric/fluorimetric rhodamine-hydroxy benzaldehyde molded Schiff base chemosensor-RL was developed and characterized. The chemosensor-RL was screened for metal ion sensing capabilities and discovered to be detecting Cu2+ ions with great sensitivity and selectivity. The complex formation between the RL and Cu2+ was characterized by 1H NMR-based titration studies as well as Job's method with 1:1 binding stoichiometry between the RL and Cu2+ ion. The limit of detection was found to be 1.16 µM. Moreover, real-time detection was successfully performed on samples such as water, natural soil from areca nut plantation, and leaching of copper cookware. As copper is an essential trace element for both humans and animals. Both deficiencies of copper and chronic exposure to high levels can be detrimental to the body. Therefore having a reliable method to detect the deposition of copper within the body may have vast application in the field of metal imaging. To test the hypothesis of in vivo Cu2+ imaging, we used Drosophila melanogaster that was exposed to chronic levels of copper(II) as a model organism. The preliminary results show that the RL was capable of detecting Cu2+ deposits within the tissue, thereby establishing the feasibility and practicality of the assay.