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DNA sensing by electrocatalysis with hemoglobin

Pheeney, Catrina G. and Guerra, Luis F. and Barton, Jacqueline K. (2012) DNA sensing by electrocatalysis with hemoglobin. Proceedings of the National Academy of Sciences of the United States of America, 109 (29). pp. 11528-11533. ISSN 0027-8424. PMCID PMC3406877. doi:10.1073/pnas.1201551109.

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Electrocatalysis offers a means of electrochemical signal amplification, yet in DNA-based sensors, electrocatalysis has required high-density DNA films and strict assembly and passivation conditions. Here, we describe the use of hemoglobin as a robust and effective electron sink for electrocatalysis in DNA sensing on low-density DNA films. Protein shielding of the heme redox center minimizes direct reduction at the electrode surface and permits assays on low-density DNA films. Electrocatalysis with methylene blue that is covalently tethered to the DNA by a flexible alkyl chain linkage allows for efficient interactions with both the base stack and hemoglobin. Consistent suppression of the redox signal upon incorporation of a single cytosine-adenine (CA) mismatch in the DNA oligomer demonstrates that both the unamplified and the electrocatalytically amplified redox signals are generated through DNA-mediated charge transport. Electrocatalysis with hemoglobin is robust: It is stable to pH and temperature variations. The utility and applicability of electrocatalysis with hemoglobin is demonstrated through restriction enzyme detection, and an enhancement in sensitivity permits femtomole DNA sampling.

Item Type:Article
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URLURL TypeDescription DOIArticle CentralArticle Information
Barton, Jacqueline K.0000-0001-9883-1600
Additional Information:© 2012 by the National Academy of Sciences. Edited by Royce W. Murray, University of North Carolina at Chapel Hill, Chapel Hill, NC, and approved May 22, 2012 (received for review March 23, 2012). Published online before print June 25, 2012. This research was supported by the National Institute of Health (GM61077) and ONR (N00014-09-1-1117). We would like to thank Donald S. Clark for an undergraduate fellowship to L.F.G. The authors thank N. Muren for discussions and contributions in fabricating the multiplexed chips. This work was completed in part in the Caltech Micro/Nano Fabrication Laboratory. Author contributions: C.G.P. and J.K.B. designed research; C.G.P. and L.F.G. performed research; C.G.P., L.F.G., and J.K.B. analyzed data; and C.G.P. and J.K.B. wrote the paper. The authors declare no conflict of interest. This article is a PNAS Direct Submission. This article contains supporting information online at
Funding AgencyGrant Number
Office of Naval Research (ONR)N00014-09-1-1117
Subject Keywords:DNA charge transport; DNA sensors; mismatch detection
Issue or Number:29
PubMed Central ID:PMC3406877
Record Number:CaltechAUTHORS:20120810-143422701
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Official Citation:Catrina G. Pheeney, Luis F. Guerra, and Jacqueline K. Barton DNA sensing by electrocatalysis with hemoglobin PNAS 2012 109 (29) 11528-11533; published ahead of print June 25, 2012, doi:10.1073/pnas.1201551109
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:33105
Deposited By: Tony Diaz
Deposited On:10 Aug 2012 22:51
Last Modified:09 Nov 2021 21:32

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