Rhodamine-based fluorescent and colorimetric sensor for zinc and its application in bioimaging

Abstract

© 2016 Published by Elsevier B.V. A rhodamine derivative ZP1, appended with two 1,2,3-triazole moieties via a diaminopropyl linker, is a chromogenic and fluorogenic sensor for Zn2+. In the presence of Zn2+, a colorless solution of ZP1 becomes pink with a maximum absorption of 555 nm and a large fluorescence enhancement (140-fold) at 579 nm (Φ = 0.12). ZP1 is highly selective with Zn2+, among other metal ions including Cd2+, with a binding constant (Ka) of 7.4 × 103M-1and a detection limit of 1 μM (65 ppb). Similar rhodamine derivatives with a shorter linker or with a single triazolyl group cannot function as a Zn2+chemosensor. ZP1 is membrane-permeable and could react with intracellular Zn2+in cultured HeLa cells.