A colorimetric chemosensor for the sequential detection of copper ion and amino acids (cysteine and histidine) in aqueous solution

摘要

A simple and selective colorimetric chemosensor 1 was reported for the sequential detection of Cu2+, cysteine (Cys) and histidine (His) in aqueous solution. The presence of Cu2+ led to a distinct naked-eye color change from pale yellow to orange. Also, the receptor enabled analysis of Cu2+ ions with a sensitivity limit of 0.37 mu M, which is far below the WHO acceptable limit (31.5 mu M) in drinking water. 1 could be also used as a practical, visible colorimetric test strip for Cu2+ (down to 10 mu M) in aqueous media. Moreover, the resulting 1-Cu2+ complex sensed cysteine and histidine with an absorption change via UV-visible or a naked-eye color change, although His and Cys were indistinguishable with the method proposed herein.