Synthesis and Application of a Novel ¡°Switch-on¡± Cyclometalated Iridium Complex Fluorescent Probe for Hypochlorite Detection

KeyWord:fluorescent probe  iridium complex  hypochlorite  synthesis  application

Abstract:

      In this paper£¬a novel sensitive fluorescent probe£ÛIr£¨bzq£©2£¨L1£©£Ý£¨PF6£©£¨bzq£¬i.e. benzoquinoline£¬and L1£¬i.e. 4'-methyl-2£¬2'-bipyridine-4-formaldehyde oxime£© was synthesized and characterized in detail£®After adding hypochlorite£¨ClO-£© in £ÛIr£¨bzq£©2£¨L1£©£Ý£¨PF6£© system£¬the fluorescence of this complex was significantly enhanced because the oxime group on L1 as the reaction site was transformed into the carboxylic acid£¬resulting in a bright visible orange-yellow light from dark brown under a 365 nm ultraviolet lamp£®Under the optimum conditions£¬the fluorescence intensity of £ÛIr£¨bzq£©2£¨L1£©£Ý£¨PF6£© probe showed a good linear relationship with hypochlorite in the concentration range of 0.1£­210 ¦Ìmol/L£¬with a detection limit of 3.08 nmol/L£®The selective and competitive experiments revealed that this probe showed better selectivity and sensitivity for ClO- than that for other ions£®The proposed method was applied to the detection of ClO- in local river samples with satisfactory recoveries of 92.4%£­103%£¬suggesting that the fluorescent probe could be used for analysis of ClO- in practical samples£®