A dual-function probe based on naphthalene diimide for fluorescent recognition of Hg2+ and colorimetric detection of Cu2+

The core-substituted naphthalene diimide (NDI-6) as a dual-function probe was synthesized conveniently, which can monitor Hg2+ by fluorescent response and serve as a naked-eye detector towards Cu2+ The strong red emission induced by the addition of Hg2+ can be ascribed to the inhibition of the twisted intramolecular charge transfer (TICT) in the excited state, based on the experimental data and theory calculation. Meanwhile, NDI-6 could be used as a reversible fluorescent probe towards Hg2+ with the aid of I- as test strips, which can be applied into the detection of real samples. (C) 2017 Elsevier B.V. All rights reserved.