Carbazole‐based dual‐functional chemosensor: Colorimetric sensor for Co<sup>2+</sup> and fluorescent sensor for Cu<sup>2+</sup> and its application
Li Liu, Xiaonan Liu, Changqing Guo, Min Fang, Cun Li, Weiju Zhu
Abstract
Abstract A new carbazole derivative CNS was prepared by the condensation of 2‐hydrazine benzothiazole with 3‐aldehyde‐6‐naphthalene‐ N ‐butyl carbazole, which could highly selectively discriminate Co 2+ and Cu 2+ in different solvent systems. CNS could enable the recognition of Co 2+ by the “naked eye,” with the color changing from colorless to pale yellow in DMSO/H 2 O (v/v = 1:1). The addition of Cu 2+ made the fluorescence emission intensity increase nearly 10 times, which was accompanied by a weak blue shift of the emission peak in CH 3 CN. Under the illumination of 365 nm ultraviolet lamp, the color of the CNS solution changed from light blue to dark blue after Cu 2+ was added. The binding process could be reasonably speculated by spectrometric titrations, 1 H NMR, mass spectrometry (MS) analysis, and density functional theory (DFT) calculation. The results of fluorescence electron microscopy showed that CNS could be used as a fluorescent sensor to detect Cu 2+ in Hela cells. In addition, CNS was successfully used for the detection of Cu 2+ in actual water samples.