A highly selective fluorescent chemosensor based on naphthalimide and Schiff base units for Cu2+ detection in aqueous medium

• Published in: Zeitschrift für Naturforschung. B, A journal of chemical sciences Vol. 72; no. 1; pp. 35 - 41
• Main Authors: Xu, Yuling, Aderinto, Stephen Opeyemi, Wu, Huilu, Peng, Hongping, Zhang, Han, Zhang, Jiawen, Fan, Xuyang
• Format: Journal Article
• Language: English
• Published: BERLIN De Gruyter 01.01.2017; Walter De Gruyter
• Subjects: Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; chemosensor; fluorescence; ion; naphthalimide; Physical Sciences; Schiff base; Science & Technology; naphthalimide; CU(II); chemosensor; SENSOR; IONS; COPPER; DOTS; SENSITIVE DETECTION; Schiff base; MERCURY; CADMIUM; fluorescence; Cu2+ ion; PROBE; WATER
• ISSN: 0932-0776; 1865-7117
• DOI: 10.1515/znb-2016-0138

A new Schiff base, 4-allylamine- -( -5-methylsalicylidene)-1,8-naphthalimide ( ), has been designed and synthesized by combining a 1,8-naphthalimide moiety as a fluorophore and a Schiff base as a recognition group. Its photophysical properties were investigated by absorption and fluorescence spectroscopy, and this sensor exhibits a high fluorescence quantum yield of 0.75–0.91 inorganic solvents of different polarity. It also shows high selectivity for Cu over other ions with fluorescence quenching in aqueous medium (pH=7.2). The reason for this phenomenon (fluorescence quenching) is attributed to the formation of a 1:1 complex between and Cu according to the Job plot and fluorescence titration. The sensor can be applied to the quantification of Cu in a linear fashion from 0.5 to 5 μM with a detection limit of 0.23 μM. Additionally, the association constant ( ) between Cu and is 1.328×10 M in aqueous media.