About the Authors

Kristen K. B. Barthel

Affiliation Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado, United States of America

Xuedong Liu

liux@colorado.edu

Affiliation Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: XL KB. Performed the experiments: KB. Analyzed the data: XL KB. Wrote the paper: XL KB.