A dual-signal half-salamo-based sensing platform for simultaneous colorimetric and fluoremetric detection of Fe3+ and reversible recognition of OH- ions

A facile bifunctional half-salamo-based sensor NQS was devised and synthesized for the detection of Fe3+ and OH- with colorimetric and fluoremetric dual-signal sensing mode. Binding with Fe3+, the original blue fluorescence signal of NQS was wholly quenched due to the paramagnetic quenching property, and a distinct color changed from colorless to yellow. On encountering OH-, a new green fluorescence signal gradually enhanced with instantaneous color change from colorless to bright yellow because of the deprotonation of phenolic hydroxyl group of NQS. Moreover, the colorimetric and fluoremetric sensing process of OH- by NQS can be converted by the addition of H+. Altogether, this work provides a new platform for selectively recognizing the biologically and environmentally important Fe3+ and OH- ions simultaneously.

Automated summary

A facile bifunctional half-salamo-based sensor NQS was developed for the simultaneous detection of Fe3+ and OH- ions using colorimetric and fluoremetric dual-signal sensing mode. Binding with Fe3+ resulted in the quenching of blue fluorescence signal of NQS and a distinct color change from colorless to yellow. On encountering OH-, the deprotonation of phenolic hydroxyl group of NQS led to the enhancement of green fluorescence signal and an instantaneous color change from colorless to bright yellow. Moreover, the addition of H+ could convert the colorimetric and fluoremetric sensing process of OH- by NQS.