TY - JOUR
T1 - A Hybrid DNA-Templated Gold Nanocluster for Enhanced Enzymatic Reduction of Oxygen
AU - Chakraborty, Saumen
AU - Babanova, Sofia
AU - Rocha, Reginaldo C.
AU - Desireddy, Anil
AU - Artyushkova, Kateryna
AU - Boncella, Amy E.
AU - Atanassov, Plamen
AU - Martinez, Jennifer S.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/9/16
Y1 - 2015/9/16
N2 - We report the synthesis and characterization of a new DNA-templated gold nanocluster (AuNC) of ∼1 nm in diameter and possessing ∼7 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 ∼15 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- 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.
AB - We report the synthesis and characterization of a new DNA-templated gold nanocluster (AuNC) of ∼1 nm in diameter and possessing ∼7 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 ∼15 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- 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.
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U2 - 10.1021/jacs.5b05338
DO - 10.1021/jacs.5b05338
M3 - Article
C2 - 26288369
AN - SCOPUS:84941775104
SN - 0002-7863
VL - 137
SP - 11678
EP - 11687
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 36
ER -