A novel rhodamine-based colorimetric and fluorescent sensor for the dual-channel detection of Cu2+ and Fe3+ in aqueous solutions

• Published in: Dyes and pigments 2013-11, Vol.99 (2), p.472-479
• Main Authors: Liu, Aifeng, Yang, Liang, Zhang, Zhenyu, Zhang, Zhilan, Xu, Dongmei
• Format: Article
• Language: English
• Subjects: Colorimetric sensor; Colorimetry; Cu2; Detection; Dual-channel; Dyes; Fe3; Fluorescent sensor; Hydrates; Hydrazines; Infrared radiation; Rhodamine; Rhodamine B; Sensors
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2013.06.007

A novel xanthene dye was designed and synthesized from rhodamine B, hydrazine hydrate and 4-chloro-7-nitro-2,1,3-benzoxadiazole. The sensing activity of the new rhodamine dye toward metal ions was carefully investigated. In H2O/CH3CN (1/1, v/v), the dye showed high selectivity and sensitivity to Cu2+ by remarkable absorption and fluorescence enhancement, while in H2O/CH3CN (99/1, v/v), the dye behaved as a high selective and sensitive turn-on fluorescent sensor for Fe3+. The detection was essentially insensitive to H+ concentration between pH 2.6 and 10.9. The sensing mechanism was explored by IR and LC–mass spectroscopic techniques and the LC–mass analysis results indicated that a 1:1 complex was formed between Cu2+ (or Fe3+) and the sensor. •A new rhodamine B-based dye is reported.•The dye can be used to monitor Cu2+ and Fe3+ in aqueous solutions.•The dye is a colorimetric and fluorescent sensor.•The sensor has high selectivity and sensitivity.•The sensor can be applied in a wide pH rang.