A new sulfite-selective probe system based on resorufin was investigated. Levulinate of resorufin exhibited a prominent chromogenic and turn-on type fluorogenic signaling toward sulfite ions in aqueous media based on the selective deprotection of the levulinate group. The sulfite-selective signaling was possible in the presence of commonly encountered anions.

The chemosignaling of the oxidant Oxone by selective desulfurization of a thioamide was investigated. Pyrene-thioamide was efficiently converted to its amide analogue by reaction with Oxone, resulting in a pronounced fluorescent turn-on type signaling. Selective signaling of Oxone in aqueous solution was possible in the presence of representative alkali and alkaline earth metal ions, as well as common anions.

Thioamide derivative with a pyrene fluorophore was smoothly transformed to its corresponding amide by Zr(4+) ions in the presence of hydrogen peroxide. The transformation was evidenced by (1)H NMR spectroscopy and the signaling was completed within 10 min after sample preparation. Interference from Ag(+) and Hg(2+) ions in Zr(4+)-selective fluorescence signaling was readily suppressed with the use of Sn(2+) as a reducing additive. Discrimination of Zr(4+) from closely related hafnium, which is a frequent contaminant in commercial zirconium, was not possible. Prominent Zr(4+)-selective turn-on type fluorescence signaling was possible with a detection limit of 4.6 × 10(-6) M in an aqueous 99% ethanol solution.

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