Real time sensor for Fe, Al, Cu & PPi through quadruple mechanistic pathways using a novel dipodal quinoline-based molecular probe.

A quinoline-based small molecular probe, HL was designed, synthesized and characterized by different spectroscopic methods. It was utilized as a multi-responsive probe for the detection of Fe, Al, Cu and PPi. It showed very selective instant turn-on fluorimetric response towards Feand Al with a detection limit in nanomolar range. Solutions of HL containing Fe or Al could sequentially sense PPi by a turn-off mechanism. Also, HL could determine the presence of Cu very selectively among a series of other metal ions by a sharp change in colour. Detection of Cu through colorimetry was further investigated by systematic UV-Vis studies and the potential of HL to act as a potential colorimetric sensor for Cu was suitably established. Filter-paper strip experiments were conducted to demonstrate the practical utility of the proposed sensor. Potential applications of HL as a sensor for pH in the acidic range has also been explored.