A reaction based chromofluorogenic turn-on probe for specific detection of fluoride over sulfide/thiols

A new reaction based probe fluorescein nosylate (R1) has been designed and synthesized for selective recognition of F- in acetonitrile (CH3CN) by exploiting both its nucleophilic and basic character. Probe R1 consists of fluorescein dye as a signalling unit while 4-nitrobenzenesulfonyl chloride as the masking unit. The F- plays the role of de-masking agent to set free the fluorescein moiety in its open form from R1 leading to significant changes in its absorption/emission profile. The detection of F- amidst of sulfide/thiols through receptors undergoing nucleophilic scission is a tedious job due to similarity in their extent of basicity/nucleophilicity. Here, we present a convenient solution for the same in the form of R1 which detects F- selectively over sulfide/thiols in CH3CN with a high detection limit of 4.6 x 10(-7) M and 2.75 x 10(-8) M determined through UV-visible and fluorescence titration data, respectively. (C) 2014 Elsevier Ltd. All rights reserved.