Pd–Ir Core–Shell Nanocubes: A Type of Highly Efficient and Versatile Peroxidase Mimic

Abstract

Peroxidase mimics with dimensions on the nanoscale have received great interest as emerging artificial enzymes for biomedicine and environmental protection. While a variety of peroxidase mimics have been actively developed recently, limited progress has been made toward improving their catalytic efficiency. In this study, we report a type of highly efficient peroxidase mimic that was engineered by depositing Ir atoms as ultrathin skins (a few atomic layers) on Pd nanocubes (i.e., Pd-Ir cubes). The Pd-Ir cubes exhibited significantly enhanced efficiency, with catalytic constants more than 20- and 400-fold higher than those of the initial Pd cubes and horseradish peroxidase (HRP), respectively. As a proof-of-concept demonstration, the Pd-Ir cubes were applied to the colorimetric enzyme-linked immunosorbent assay (ELISA) of human prostate surface antigen (PSA) with a detection limit of 0.67 pg/mL, which is ∼110-fold lower than that of the conventional HRP-based ELISA using the same set of antibodies and the same procedure.

AuPt Alloy Nanostructures with Tunable Composition and Enzyme-like Activities for Colorimetric Detection of Bisulfide

“…Compared with natural enzymes, nanostructured artificial enzymes have several advantages, such as easy synthesis, facile storage and high catalytic stability against stringent conditions. Until now, a variety of nanomaterials, including metal oxides345, metal sulfides67, noble metals891011, carbon1213, and their combined nanostructures1415 have been explored to exhibit enzyme-like activities. Because of the quantum size and surface effect, nanoparticles generally exhibit superior catalytic activity and intrinsic ability to generate or scavenge reactive oxygen species161718.…”

“…Several metal nanomaterials (e.g., Pt, Au, Pd, Ir) have been discovered for their intrinsic enzyme-like activities891011. Among them, Pt family NPs recently have been found to exhibit multiple enzyme-like activities similarly to peroxidase, polyphenol oxidase, ferroxidase, catalase and SOD9222324.…”

Shape-Controlled Metal Nanocrystals for Heterogeneous Catalysis

“…In this case, manipulation of the rates corresponding to the reduction and deposition of Ir, as well as acceleration of surface diffusion for the Ir adatoms, allowed the formation of a uniform shell with a smooth surface. The Pd@Ir core-shell structures were also explored for catalyzing the decomposition of hydrous hydrazine and as peroxidase mimics, which play a crucial role in enzyme biochemistry (84). In addition to reducing the mass loading, core-shell nanocrystals offer a practical means for engineering the lattice strain on the surface of catalytic particles.…”

Boosting the Peroxidase-Like Activity of Nanostructured Nickel by Inducing Its 3+ Oxidation State in LaNiO3 Perovskite and Its Application for Biomedical Assays

“…Till now, lots of functional nanomaterials (e.g., carbon based, metal oxide based and metal based nanomaterials) have been explored to mimic peroxidase 15, 17, 39-41. Among them, transition metal oxide nanomaterials had been extensively studied due to their excellent catalytic activities, high stability, low cost and ease of preparation 6, 10, 11.…”