A novel colorimetric sensor based on a diarylethene derivative for selective detection of Cu(ii)

Abstract

A new diarylethene derivative with excellent photochromism and remarkable fatigue resistance in solution has been synthesized. The interaction between its closed-ring isomer and Cu²⁺ caused a notable change in the absorption spectrum with a significant color change from purple to red. However, the diarylethene derivative did not show any obvious change upon interaction with other metal ions. The 1 : 1 binding stoichiometry between Cu²⁺ and the derivative was obtained using Job's plot and ESI-MS analysis. A binding constant of (1.29 ± 0.17) × 10⁴ M⁻¹ for the diarylethene–Cu²⁺ complex was calculated from the Benesi–Hildebrand plot. The detection limit for the analysis of Cu²⁺ ions was found to be 1.62 × 10⁻⁶ mol L⁻¹.