Two birds with one stone: A near-infrared AIE fluorescent probe for highly selective recognition of Cu2+/GSH and bioimaging

Although notable progress has been made in the identification of Cu2+ and glutathione (GSH), probes that can specifically recognize them simultaneously are still rare. Herein, we designed, synthesized, and characterized a fluorescent probe QA with aggregation-induced emission characteristics, a near-infrared emission wavelength (688 nm), a large Stokes shift ( Delta lambda = 263 nm), and specific sequential recognition of Cu2+ and GSH. Compared with other probes, QA exhibits a fast fluorescence "ON-OFF" response to Cu2+, and its low limit of detection (LOD) toward Cu2+ is 3.53 x 10-8 M. Moreover, it can also detect Cu2+ in actual water samples. Moreover, QACu2+ shows high sensitivity to GSH with an LOD of 3.47 x 10-7 M. Notably, the toxicity of QA is so low that it can recognize Cu2+ and GSH in various models, including HepG-2 cells, Caenorhabditis elegans, and adult mice, implying that it is a favorable applicant to detect Cu2+ and GSH in vitro and in vivo.