A selective colorimetric sensor for Cu2+ in aqueous solution

We synthesized a novel Schiff-based receptor 1, and investigated its binding properties toward various metal ions. Receptor 1 showed a dramatic color change from colorless to red which could easily be detected by the naked-eye upon binding with Cu2+. The association constant for 1 center dot Cu2+ in DMSO/H2O (v/v, 1:9) was calculated to be 1.98 x 10(8) M-1. With the addition of Na(2)EDTA to a mixture of receptor 1 and Cu2+, the solution changed back to its original colorless appearance instantly. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.