Lentinan stabilized bimetallic PdPt₃ dendritic nanoparticles with enhanced oxidase-like property for L-cysteine...

The development of nanozymes with enhanced catalytic activity has been drawing great interest. Lentinan with special structure may be used to prepare bimetallic nanomaterials to enhance their catalytic activity. Herein, lentinan stabilized PdPt₃ dendritic nanoparticles (PdPt₃-LNT NDs) were prepared through reduction of Na₂PdCl₄ and K₂PtCl₄ with a molar ratio of 1:3 using lentinan as a biological template. PdPt₃-LNT NDs had dendritic shape with size of 10.76 ± 1.82 nm. PdPt₃-LNT NDs had the hydrodynamic size about 25.7 nm and the zeta potential between -1.4 mV and - 4.9 mV at different pH. Furthermore, PdPt₃-LNT NDs catalyzed 3,3',5,5'-tetramethylbenzidine (TMB) to produce oxidized TMB, suggesting their oxidase-like property. The catalytic activity of PdPt₃-LNT NDs was the highest when pH was 4 and the temperature was 40 °C. The catalytic mechanism was the generation of reactive oxygen species^- from O₂ catalyzed by PdPt₃-LNT NDs. More importantly, L-cysteine detection method was set up based on the oxidase-like property of PdPt₃-LNT NDs. This method had wide linear range for 0-200 μM and low detection limit for 3.099 μM. Taken together, PdPt₃-LNT NDs have good potential applications in bio-related detection in the future.