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

A bifunctional half-salamo-based sensor NQS was developed for simultaneous detection of Fe 3+ and OH − ions with colorimetric and fluoremetric dual-signal sensing mode. • A bifunctional half-salamo-based sensor NQS was devised and synthesized. • Sensor NQS exhibits good sensing performance toward Fe 3+ and OH − based on colorimetric and fluoremetric dual-signal sensing mode. • The determination of Fe 3+ and OH − using convenient paper strip was successfully applied. A facile bifunctional half-salamo-based sensor NQS was devised and synthesized for the detection of Fe 3+ and OH − with colorimetric and fluoremetric dual-signal sensing mode. Binding with Fe 3+ , 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 Fe 3+ and OH − ions simultaneously.