1. Department of Chemical and Biomolecular Engineering, ‡Richard E. Smalley Institute for Nanoscale Science and Technology, §Department of Chemistry, ⊥Department of Electrical and Computer Engineering, ∥Department of Physics and Astronomy, #Department of Bioengineering, △Laboratory for Nanophotonics and the Rice Quantum Institute, ▽Department of Civil and Environmental Engineering, Rice University, 6100 Main Street, Houston, Texas 77005-1892, United States