Electrocatalytic Oxidation of Alcohols, Tripropylamine, and DNA with Ligand-Free Gold Nanoclusters on Nitrided Carbon

• Published in: ChemElectroChem Vol. 3; no. 12; pp. 2100 - 2109
• Main Authors: Yao, Huiqin, Liu, Ben, Mosa, Islam M., Bist, Itti, He, Jie, Rusling, James F.
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 01.12.2016; John Wiley & Sons, Inc
• Subjects: Alcohol; Alcohols; Amines; Carbon; Deoxyribonucleic acid; DNA; electrocatalytic oxidation; Electrochemical impedance spectroscopy; Gold; gold nanoclusters; Ligands; Nanostructure; Oxidation; tripropylamine; alcohol; tripropylamine; DNA; electrocatalytic oxidation; gold nanoclusters
• ISSN: 2196-0216; 2196-0216
• DOI: 10.1002/celc.201600283

Electrocatalytic properties of ligand‐free gold nanoclusters (AuNCs, <2 nm) grown on nitrided carbon supports (denoted as AuNCs@N‐C) were evaluated for the oxidation of representative organic molecules including alcohols, an amine, and deoxyguanosine in oligonucleotides. AuNCs@N‐C catalysts were incorporated into films of architecture {PDDA/AuNCs@N‐C}n by using layer‐by‐layer assembly with oppositely charged poly(diallyldimethylammonium) (PDDA) on pyrolytic graphite (PG) electrodes. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were used to survey the electrocatalytic properties of these AuNCs@N‐C films. Ligand‐free AuNCs in these films demonstrated excellent electrocatalytic oxidation activity with maximum peak currents and the lowest potentials for oxidizing ethanol, propanol, and tripropylamine (TprA) compared to controls with Au‐surface capping agents or to larger sized Au nanocrystals on the nitrided carbon supports. EIS kinetic studies showed that ligand‐free AuNCs films have the smallest charge‐transfer resistance, largest electrochemically active surface area, and largest apparent standard rate constants, as compared to the control films for all compounds examined. DNA films on AuNCs@N‐C were oxidized at deoxyguanosine moieties with good catalytic activity that depended on charge transport within the films. Good as gold: Ligand‐free Au nanoclusters supported on nitrided carbon nanoparticles and assembled into layer‐by‐layer films of {PDDA/AuNCs@N‐C}n are found to be highly active for the electrocatalytic oxidation of alcohols, an amine, and DNA.