A highly selective colorimetric and fluorescent probe for Cu2+ based diarylethene with a diaminomaleonitrile unit

Abstract

A novel photochromic diarylethene derivative containing a diaminomaleonitrile unit (1O) was synthesized and its colorimetric and fluorescent turn-on sensing of Cu2+ in acetonitrile solution was demonstrated. Both of its open- and closed-loop isomers (1O and 1C) were highly selective for Cu2+ with obvious absorption and color transforms. Moreover, the addition of Cu2+ enhanced the fluorescence of 1O up to 174-fold with the concomitant color change from colorless to blue. The limit of detections (LODs) for Cu2+ was determined to be 1.76 × 10−8 mol L−1. The stoichiometry of 1: 1 between the probe 1O and Cu2+ was measured in Job’s plot and ESI-MS. Most remarkably, the probe 1O could be used to detect Cu2+ in test strip.