A novel 6-quinoxalinamine-based fluorescent probe for real-time detection of palladium(II) ions in pure water and bio-imaging

A novel quinoxalinamine-containing fluorescent probe (LK) was designed and synthesized based on coordination for real-time detection of Pd2+. LK was easily obtained in high yield by the Suzuki cross-coupling reaction. The quinoxaline group provides the sensor LK with good water-solubility, which is important for monitoring in biological systems. The probe possessed large Stokes shifts and excellent selectivity for detecting Pd2+ in the presence of various potential interfering metal ions. The detection limit (22 nM) was far lower than the criterion of the World Health Organization in drinking water. Moreover, LK displayed high sensitivity for identification of Pd2+ in real water samples. More importantly, the sensor LK succeeded in imaging detection of Pd2+ in live cells with good membrane permeability and low toxicity.