title: Nanodiamond-Gold Nanocomposites with the Peroxidase-Like Oxidative Catalytic Activity.
abstract: Novel nanodiamond-gold nanocomposites (NDAus) are prepared, and their oxidative catalytic activity is examined. Gold nanoparticles are deposited on carboxylated nanodiamonds (NDs) by in situ chemical reduction of gold precursor ions to produce NDAus, which exhibit catalytic activity for the oxidation of o-phenylenediamine in the presence of hydrogen peroxide similarly to a peroxidase. This remarkable catalytic activity is exhibited only by the gold nanoparticle-decorated NDs and is not observed for either Au nanoparticles or NDs separately. Kinetic oxidative catalysis studies show that NDAus exhibit a ping-pong mechanism with an activation energy of 93.3 kJ mol-1, with the oxidation reaction rate being proportional to the substrate concentration. NDAus retain considerable activity even after several instances of reuse and are compatible with a natural enzyme, allowing the detection of xanthine using cascade catalysis. Association with gold nanoparticles makes NDs a good carbonic catalyst due to charge transfer at the metal-carbon interface and facilitated substrate adsorption. The results of this study suggest that diverse carbonic catalysts can be obtained by interfacial incorporation of various metal/inorganic substances.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul, Korea 03722.
authors.forename: Min-Chul
authors.initials: MC
authors.lastname: Kim
authors.affiliation: School of Chemical Engineering and Material Science, Chung-Ang University , 84 Heukseok-ro, Dongjak-gu, Seoul, Korea 06980.
authors.forename: Dukhee
authors.initials: D
authors.lastname: Lee
authors.affiliation: College of Pharmacy, Dongguk University , Goyang, Gyeonggi 10326 Korea.
authors.forename: Seong Hoon
authors.initials: SH
authors.lastname: Jeong
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul, Korea 03722.
authors.forename: Sang-Yup
authors.initials: SY
authors.lastname: Lee
authors.affiliation: School of Chemical Engineering and Material Science, Chung-Ang University , 84 Heukseok-ro, Dongjak-gu, Seoul, Korea 06980.
authors.forename: Eunah
authors.initials: E
authors.lastname: Kang
keywords: catalysts; gold; hybrids; nanodiamonds; oxidation