Highly selective fluorescent recognition of glutathione by using a water soluble binaphthyl aldehyde

A water soluble binaphthyl-based aldehyde was designed and synthesized. This compound in combination with Zn(OAc)₂ is found to exhibit greatly enhanced fluorescence in the presence of GSH in aqueous solution (pH = 7.5) but give little or no fluorescence enhancement in the presence of cysteine, homocysteine and other amino acids. This remarkable selectivity makes this probe potentially useful for the analysis of the biologically important GSH.