A Schiff-base-modified Cu nanocluster with redox dual-catalytic sites and fluorescence sensing for the degradation and detection of atrazine.

Atrazine is a widely used and heavily contaminating pesticide. In this work, we designed and synthesized a versatile catalyst for the degradation and fluorescent detection of atrazine. This catalyst consists of Cu clusters modified by a Schiff base. The combination of Cu clusters and Schiff base enables it to act as a catalyst with the dual roles of oxidation and reduction. The inclusion of the Schiff base also narrows the band gap of Cu clusters and accelerates the redox electron transfer, leading to the degradation of atrazine up to 98%. Furthermore, the red fluorescence of Cu clusters and the green fluorescence of Schiff base allow this catalyst to sense atrazine like a sensor by a change in fluorescence color. The limit of detection for atrazine is as low as 0.1 nM and visual limit of detection is 10 nM. The mechanisms of catalysis and fluorescence sensing of the catalyst are verified by mass spectrometry and density functional theory. This multi-functional catalyst has great application potential in environmental protection, health and safety and other fields.