Symmetric fluorescent probes for the selective recognition of Ag-ion via restricted C=N isomerization and on-site visual sensing applications

摘要

Naphthalene based salen type fluorescent chemosensors have been designed and synthesized for the highly selective detection of silver ions by fluorimetry. These probes 1, 2 and 3 sense Ag+ over other cations as fluorescence 'on-off behaviour. A possible mechanism is proposed, where the heavy atom effect of silver ion overcomes the effect of C=N isomerization and intramolecular restricted torsional rotation through the C-C single bond between the naphathalene and the benzene moieties. These chemosensors are further utilized to detect Ag+ as strip tests and solid supported silica gel material. These results are further supported by the theoretical calculations. (C) 2017 Elsevier B.V. All rights reserved.