A simple but effective colorimetric and far-red to near-infrared fluorescent probe for palladium and its application in living cells

In this work, a new colorimetric and far-red to near-infrared fluorescent turn-on probe for rapid detection of palladium was reported. This probe uses a readily available seminaphthorhodafluor dye as the fluorophore and an allylcarbonate moiety as the reaction site. Based on the Pd-0-triggered cleavage reaction, this probe shows rapid (within 2 min), selective, and sensitive response for palladium with different oxidation states (Pd-0, or Pd2+ and Pd4+ in the presence of PPh3) in almost wholly aqueous solution under mild conditions, accompanied by distinct color changes and significant fluorescent turn-on signal in the far-red to near-infrared region. The detection limit of this probe for Pd-0 was determined to be as low as 1.6 nM in solution. In addition, a sensitive bioimaging of palladiun in living cells can be achieved with a low level of this probe (2 mu M), indicating the new developed probe has great potential for palladium detection in both solution and living systems.