Highly Sensitive Fluorescence Detection of Hg 2+ Based on a Water-soluble Conjugated Polymer with Carboxylate Groups

A label-free, highly selective, and highly sensitive fluorescent sensor to detect Hg 2+ was developed using a water-soluble conjugated polymer with carboxylate groups (poly(2,5-bis(sodium 4-oxybutyrate)-1,4-phenylethynylene- alt -1,4- phenyleneethynylene, PPE-OBS) in this work. The fluorescence of PPE-OBS would be quenched because of the effect among the unique coordination-induced aggregation and electron transfers of PPE-OBS toward Hg 2+ . The linear relationship between the fluorescence intensity and concentration of Hg 2+ was observed within the range from 6 × 10 −8 to 8 × 10 −5 mol L −1 (R 2 = 0.9985), and the limit of detection was 2.10 × 10 −9 mol L −1 . The proposed method was applied to detect Hg 2+ in environmental water samples, and satisfactory results were obtained.