Synergetic Peroxidase-Mimic Catalytic Activity of Noble-Metal-Decorated Lithium Niobate Nanozymes for Potential Biological Applications

In this paper, we report a simple, facile, and efficientmethodto obtain LiNbO3/Au and LiNbO3/Pt nanoparticlescomposed of LiNbO3 NPs (LN NPs) (30 nm) and ultrasmallnanoparticles (<5 nm, seeds) of Au and Pt, respectively. The synthesisof the nanocomposites followed a simple layer-by-layer method introducingbranched poly(ethyleneimine) (BPEI) as a linker. By varying the volumeof metal seeds dispersion added to the LN coated with BPEI, the loadingof metal on the surface of the LN is controlled. The morphology ofthe as-prepared composite is characterized by transmission electronmicroscopy (TEM), energy-dispersive spectrometry (EDS), and dynamiclight scattering (DLS). Its applicability as peroxidase mimics isinvestigated and compared to the separated counterparts (LN NPs, LN@BPEI,AuSeeds, PtSeeds, and a simple mixture of LN NPs and metal seeds).The synthesized nanoparticles follow the Michaelis-Menten kineticmodel with enhanced catalytic activity compared to the metal seedsalone. This intrinsic peroxidase activity makes them promising candidatesfor applications in biomedicine. In particular, the low Michaelisconstant K (m) and high maximum velocity V (max) for the H2O2 are ofgreat interest for H2O2 sensing and generationof reactive oxygen species for antimicrobial applications.