Fluorescent carbazolyldithiane as a highly selective chemodosimeter via protection/deprotection functional groups: a ratiometric fluorescent probe for Cd(II)

A carbazole-based bis-dithiane (1) was rationally constructed in a straightforward manner for the selective and ratiometric fluorescent detection of Cd2+ with the concept of aldehyde group protection/deprotection. The probe showed a ratiometric fluorescent response to Cd2+ with a large emission wavelength shift (>50 nm) and displayed high selectivity for Cd2+ over other metal ions due to distinct deprotection conditions. In addition, a Cd2+-promoted dethioacetalization mechanism was proposed.