A differentially selective sensor with fluorescence turn-on response to Zn2+ and dual-mode ratiometric response to Al3+ in aqueous media

A novel quinoline-coumarin (QC) fluoroionophore conjugated by means of a triazolyl-pyrrolidinyl linker exhibits differential dual selectivity for Zn2+ and Al3+ in mixed media. QC acts as a turn on fluorescence sensor for Zn2+ while exhibiting overall ratiometric selectivity for Al3+ in aqueous media. Moreover, QC exhibited preferential second mode of selectivity for Al3+ as it ratiometrically displaces Zn2+ from the [QC + Zn2+] complex.