Enhanced Multiple Enzymelike Activity of PtPdCu Trimetallic Nanostructures for Detection of Fe²⁺ and Evaluation of Antioxidant Capability

Abstract

Metallic nanozymes attracted broad interest because of their efficient catalytic activities and wide applications in biological detection and therapeutics. In this study, PtPdCu trimetallic nanoalloys (TNAs) are prepared by chemical coreduction of Pt2+, Pd2+, and Cu2+ in an aqueous solution. The formation of PtPdCu TNAs is characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive system (EDS), and X-ray photoelectron spectroscopy (XPS). Compared to PtPd bimetallic nanoalloys (BNAs) and commercial Pt/C, PtPdCu TNAs have enhanced enzymelike activities, including peroxidase, oxidase (ferroxidase), and catalase, as well as increased DPPH free radical scavenging ability. Due to the synergistic effect between heteroatoms, the incorporation of Cu into Pt and Pd to form trimetallic structure not only exposes more active surfaces but also causes a change in the electronic structure, which is beneficial to improve the enzymelike catalytic activity. Using the ferroxidase-like and peroxidase-like activity of PtPdCu TNAs, we demonstrate the applications of PtPdCu TNAs in selective detection of Fe2+ in oral supplements and evaluation of the antioxidant capacity of natural antioxidants and tea extracts. Three natural antioxidants tannic acid (TA), gallic acid (GA), and ascorbic acid (AA) are found to show different inhibitory behaviors on peroxidase-like activity of PtPdCu and share the order of antioxidant capability TA > GA > AA.

Accelerated Mimetic Oxidase Activity of Polydopamine-Dressed PdCu Nanozyme for the Detection of Ascorbic Acid Related Bioenzymes

“…17 In addition, the Pd(0) binding energies of Pd 3d 5/2 and Pd 3d 3/2 in PDA-PdCu are slightly positively shifted compared to those in PDA-Pd, suggesting an electron pass route from Pd to Cu. 19,43 These results demonstrate that the electronic states of Pd are successfully modulated by PDA coating and Cu doping. Previous literature reported that metallic state is more beneficial to boost the catalytic activity of precious metals.…”

“…22,23 The surface structures and properties of nanozymes, including morphology, rigidity, wettability, charge, etc., can be modified with metal ions, small molecules, and polymers. 19,22 Till now, various types of polymers, such as polylactic acid, 24 polyethyleneimine, 25 and polydopamine (PDA), 26 have been verified as a coating on the surface of nanomaterials. In comparison, PDA coating polymerized from dopamine is superior to other polymers because PDA can virtually deposit onto and form functional coatings on the surfaces of nearly all types of organic and inorganic materials due to its intrinsic adhesive and cohesive properties as well as abundant functional moieties.…”

Ti3C2 nanosheets with broad-spectrum antioxidant activity for cytoprotection against oxidative stress

“…Pt based and metal oxide) oen function to mimic multiple redox enzymes (oxidase, SOD, peroxidase and catalase). [21][22][23][24][25] Such multiple enzymelike activity enables nanozymes with antioxidant activity while also having pro-oxidative functions. Therefore, it is highly required to develop ideal antioxidant nanomaterial with high efficiency and broad spectrum for biomedical study and clinical applications.…”

Biocatalytic and Antioxidant Nanostructures for ROS Scavenging and Biotherapeutics

“…[ 12 ] Different types of noble metal NPs, such as Au, Ag, platinum group metals (Pd, Pt, Ru, Rh, Os, Ir), and their alloy NPs, have been widely used in different fields, including sensing, biomedicine, and catalysis. [ 104–112 ]…”