Two highly selective fluorescence probes for imaging Pd2+ in cells and mice

Abstract

Two rhodamine-based probes were designed and prepared, which exhibited highly sensitive and selective fluorescence enhancement upon binding to Pd2+ by UV–vis and fluorescence spectroscopies. Meanwhile the distinct color changes and rapid switch-on fluorescence also provided “naked-eyes” detection for Pd2+ over a broad pH range. The recognition mechanism was explored through Job’s plot, MS data, IR spectra and related theoretical calculations. Furthermore, the probes were applied for biological imaging to confirm that they can be used for monitoring Pd2+ in living cells (L929 and A549 cells) and living mice with satisfying results, which further demonstrated their value of practical applications in environmental and biological systems.