Colorimetric and fluorogenic signaling of fluoride ions by thiophosphinated dichlorofluorescein

• A new fluoride-selective probe based on thiophosphinated dichlorofluorescein was developed.
• Dual signaling was realized by fluoride-selective hydrolysis of the latent probe.
• Possible interferences from metal ions were suppressed by using a masking agent.
• Detection limit of the probe for the determination of fluoride ions was 9.8 nM.

Highly selective chemosignaling behavior of thiophosphinated dichlorofluorescein towards fluoride ions was investigated. Prominent chromogenic and fluorescence turn-on type signaling was realized by employing fluoride-selective cleavage of the latent thiophosphinated probe in mixed aqueous media. The signaling process was confirmed by the UV–vis, fluorescence measurements as well as 1H and 31P NMR spectroscopy. Possible interferences from Hg2+ and Cu2+ ions were readily suppressed by using diethylenetriaminepentaacetic acid as a masking agent. With the aid of the masking agent, the probe also showed potentially useful sensing ability for the determination of fluoride ions in practical samples of tap water and simulated wastewater. The detection limit of the probe in the determination of fluoride ions was 9.8 nM.

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