A New, Highly Potent 1,8-Naphthalimide-based Fluorescence “Turn off” Chemosensor Capable of Cu2+ Detection in China's Yellow River Water Samples

Article abstract of DOI:10.1002/jccs.201700308

A new 1,8-naphthalimide-based fluorescence “turn off” chemosensor, N-phenyl-4-(3,3′-((2-aminoethyl)azanediyl)dipropanoic acid)-1,8-naphthalimide (MAST), for the detection of Cu²⁺ was synthesized. Upon treatment with Cu²⁺, in coexistence with various competitive metal ions in HEPES-buffered dimethylsulfoxide (DMSO) solution (v/v, 1:1; pH 7.4), MAST displayed a high selectivity toward Cu²⁺ with a fluorescence quenching of 83.67%. Additionally, a good linear response of MAST for the detection of Cu²⁺ was obtained in the concentration range of 10 × 10^?6 to 50 × 10^?6 M. A 1:1 stoichiometric interaction of MAST with Cu²⁺ was observed, and the association constant and detection limit were calculated to be 1.37 × 10⁶ and 0.69 × 10^?8 M, respectively. The sensing mechanism of the chemosensor toward Cu²⁺ was proposed due to the effect of the paramagnetic nature of Cu²⁺ and reverse-photo-induced electron transfer (PET) process. Ultimately, the proposed chemosensor was applied to quantify Cu²⁺ in real-world water samples, with excellent recovery rates of 98.00–109.80% observed.