Triphenylphosphine-assisted highly sensitive fluorescent chemosensor for ratiometric detection of palladium in solution and living cells

Accurate and sensitive detection of palladium (Pd) is essential for both environmental and human health applications. This paper describes a triphenylphosphine (PPh₃)-assisted highly sensitive fluorescent chemosensor for ratiometric detection of Pd²⁺ concentrations up to 300 nM with an LOD of 1 nM. During the detection, PPh₃ plays a crucial role in improving the sensitivity of this chemosensor. The chemosensor also has suitable water-solubility which allows detection of Pd²⁺ in solution. Our studies show that it exhibits excellent selectivity toward Pd²⁺ and undergoes a color change from colorless to yellow to allow visual detection of Pd²⁺. Besides detection in solution, this chemosensor also shows great potential as an imaging reagent to detect Pd²⁺ as low as 0.03 ppm in diverse cells.