A Hybrid DNA-Templated Gold Nanocluster For Enhanced Enzymatic Reduction of Oxygen

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• 作者：Saumen Chakraborty ; Sofia Babanova ; Reginaldo C. Rocha ; Anil Desireddy ; Kateryna Artyushkova ; Amy E. Boncella ; Plamen Atanassov ; Jennifer S. Martinez
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：September 16, 2015
• 年：2015
• 卷：137
• 期：36
• 页码：11678-11687
• 全文大小：616K
• ISSN：1520-5126

文摘

We report the synthesis and characterization of a new DNA-templated gold nanocluster (AuNC) of 鈭? nm in diameter and possessing 鈭? Au atoms. When integrated with bilirubin oxidase (BOD) and single walled carbon nanotubes (SWNTs), the AuNC acts as an enhancer of electron transfer (ET) and lowers the overpotential of electrocatalytic oxygen reduction reaction (ORR) by 鈭?5 mV as compared to the enzyme alone. In addition, the presence of AuNC causes significant enhancements in the electrocatalytic current densities at the electrode. Control experiments show that such enhancement of ORR by the AuNC is specific to nanoclusters and not to plasmonic gold particles. Rotating ring disk electrode (RRDE) measurements confirm 4e^{鈥?/sup> reduction of O₂ to H₂O with minimal production of H₂O₂, suggesting that the presence of AuNC does not perturb the mechanism of ORR catalyzed by the enzyme. This unique role of the AuNC as enhancer of ET at the enzyme-electrode interface makes it a potential candidate for the development of cathodes in enzymatic fuel cells, which often suffer from poor electronic communication between the electrode surface and the enzyme active site. Finally, the AuNC displays phosphorescence with large Stokes shift and microsecond lifetime.}