An EDTA promoted coordination induced disaggregation for specific Hg2+ detection

• Published in: Dyes and pigments Vol. 113; pp. 181 - 188
• Main Authors: Zhu, Huijun, Fan, Juan, Chen, Hangqing, Tang, Zhenwei, Wang, Guimei, Fu, Nanyan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2015
• Subjects: Disaggregation; Dithiocarbamate; EDTA; Fluorescent probe; Mercury; Squaraine; Disaggregation; Dithiocarbamate; EDTA; Mercury; Fluorescent probe; Squaraine
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2014.07.041

In this work, a novel fluorescent sensing strategy was developed for the detection of Hg2+ with excellent sensitivity and selectivity using a metal-induced disaggregation of aggregated squaraine molecules with the help of ethylenediaminetetreaacetic acid (EDTA). This EDTA promoted probe exhibited a specific “turn on” fluorescent response to Hg2+ with a detection limit of 7.6 × 10−9 M (3σ/k). Owning to the high coordinating ability of EDTA and dithiocarbamate tethered squaraine dye toward Hg2+, the disaggregation process could be improved by EDTA via the formation of squaraine-Hg2+-EDTA trinary complex, resulting in a greater fluorescent release, and this novel phenomenon has been confirmed by light scattering experiments, 1H NMR, IR and MS. [Display omitted] •An EDTA promoted fluorescent probe of Hg2+ has been designed and synthesized.•The sensing mechanism is based on coordination induced disaggregation of squaraine.•The probe showed high selectivity and sensitivity.•A trinary complex among squaraine, EDTA and Hg2+ has been detected.