Discrimination of Pd0 and Pd2+ in solution and in live cells by novel light-up fluorescent probe with AIE and ESIPT characteristics

A novel and simple light-up fluorescent probe (PASPy-al) with a D-pi-A structure based on AIE as well as ESIPT processes was designed for highly selective discrimination of Pd2+ and Pd-0. PASPy-al displayed a large Stokes shift (95 nm), a high light-up ratio (116 fold) and a low limit of detection (LOD: 96 nM) toward Pd-0. Moreover, the practical applications of PASPy-al for detection of Pd-0 in environmental, human urine and pharmaceutical samples were realized, indicating the unique advantages of designing anti-ACQ fluorescent probes based on AIE and ESIPT mechanism. Fluorescence imaging of Pd-0 in live cells was realized by using PASPy-al. Furthermore, imaging of Pd-0 generation in live cells was also realized by in situ reduction of Pd2+ to Pd-0 in the presence of reducing agent like CO, indicating the potential ability of this probe for further fluorescent imaging of cellular reducing agent. The easy preparation of probe PASPy-al plus their excellent parameters would make it a simple to handle probe for detection of Pd-0 both in practical samples and in live cells. Elsevier B.V. All rights reserved.