title: Platinum Nanoparticles: Efficient and Stable Catechol Oxidase Mimetics.
abstract: Although enzyme-like nanomaterials have been extensively investigated over the past decade, most research has focused on the peroxidase-like, catalase-like, or SOD-like activity of these nanomaterials. Identifying nanomaterials having oxidase-like activities has received less attention. In this study, we demonstrate that platinum nanoparticles (Pt NPs) exhibit catechol oxidase-like activity, oxidizing polyphenols into the corresponding o-quinones. Four unique approaches are employed to demonstrate the catechol oxidase-like activity exerted by Pt NPs. First, UV-vis spectroscopy is used to monitor the oxidation of polyphenols catalyzed by Pt NPs. Second, the oxidized products of polyphenols are identified by ultrahigh-performance liquid chromatography (UHPLC) separation followed by high-resolution mass spectrometry (HRMS) identification. Third, electron spin resonance (ESR) oximetry techniques are used to confirm the O2 consumption during the oxidation reaction. Fourth, the intermediate products of semiquinone radicals formed during the oxidation of polyphenols are determined by ESR using spin stabilization. These results indicate Pt NPs possess catechol oxidase-like activity. Because polyphenols and related bioactive substances have been explored as potent antioxidants that could be useful for the prevention of cancer and cardiovascular diseases, and Pt NPs have been widely used in the chemical industry and medical science, it is essential to understand the potential effects of Pt NPs for altering or influencing the antioxidant activity of polyphenols.
authors: Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , College Park, Maryland 20740, United States.|Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States.
authors: Yi
authors: Y
authors: Liu
authors: Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , College Park, Maryland 20740, United States.
authors: Haohao
authors: H
authors: Wu
authors: Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , College Park, Maryland 20740, United States.
authors: Yu
authors: Y
authors: Chong
authors: Division of Bioanalytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , College Park, Maryland 20740, United States.
authors: Wayne G
authors: WG
authors: Wamer
authors: Biochemical Toxicology Division, National Center for Toxicological Research, U.S. Food and Drug Administration , Jefferson, Arkansas 72079, United States.
authors: Qingsu
authors: Q
authors: Xia
authors: Biotranex LLC , Monmouth Junction, New Jersey 08852, United States.
authors: Lining
authors: L
authors: Cai
authors: Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States.
authors: Zhihong
authors: Z
authors: Nie
authors: Biochemical Toxicology Division, National Center for Toxicological Research, U.S. Food and Drug Administration , Jefferson, Arkansas 72079, United States.
authors: Peter P
authors: PP
authors: Fu
authors: Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , College Park, Maryland 20740, United States.
authors: Jun-Jie
authors: JJ
authors: Yin
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry* / Q000378:metabolism; D002109:Caffeic Acids / Q000737:chemistry; D002384:Catalysis; D002392:Catechin / Q000737:chemistry; D004156:Catechol Oxidase / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004578:Electron Spin Resonance Spectroscopy; D013058:Mass Spectrometry; D053768:Metal Nanoparticles / Q000737:chemistry*; D014442:Monophenol Monooxygenase / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010984:Platinum / Q000737:chemistry*; D059808:Polyphenols / Q000032:analysis / Q000737:chemistry; D011794:Quercetin / Q000737:chemistry; D011809:Quinones / Q000032:analysis / Q000737:chemistry
chemical_list: D002109:Caffeic Acids; D059808:Polyphenols; D011809:Quinones; D010984:Platinum; D002392:Catechin; D011794:Quercetin; D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase; D010100:Oxygen; C040048:caffeic acid
keywords: catechol oxidase-like activity; enzyme mimetics; heterogeneous catalysts; oxidation of polyphenols; platinum nanoparticles