1. California NanoSystems Institute, University of California, Los Angeles, Los Angeles,
California 90095, United States
2. Department of Chemistry and
Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
3. Department of Chemistry, The Pennsylvania State University, University Park,
Pennsylvania 16802, United States
4. Department of Physics, The Pennsylvania State University, University Park,
Pennsylvania 16802, United States
5. Department of Psychiatry and Semel
Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, California
90095, United States
6. Department of Materials Science
and Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States