About the Authors

Qian Wang

Affiliation Department of Physics, University of Houston, Houston, Texas, United States of America

Kao-Chen Liang

Affiliation Department of Physics, University of Houston, Houston, Texas, United States of America

Arkadiusz Czader

Affiliation Department of Chemistry, University of Houston, Houston, Texas, United States of America

M. Neal Waxham

Affiliation Department of Neurobiology and Anatomy, University of Texas, Health Science Center, Houston, Texas, United States of America

Margaret S. Cheung

mscheung@uh.edu

Affiliation Department of Physics, University of Houston, Houston, Texas, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: MNW MSC. Performed the experiments: QW KCL AC. Analyzed the data: QW KCL AC MNW MSC. Contributed reagents/materials/analysis tools: AC MNW MSC. Wrote the paper: MNW MSC.