Self-Assembly of Large Gold Nanoparticles for Surface-Enhanced Raman Spectroscopy.
Performance of portable technologies from mobile phones to electric vehicles is currently limited by the energy density and lifetime of lithium batteries. Expanding the limits of battery technology requires in situ detection of trace components at electrode-electrolyte interphases. Surface-enhance Raman spectroscopy could satisfy this need if a robust and reproducible substrate were available. Gold nanoparticles (Au NPs) larger than 20 nm diameter are expected to greatly enhance Raman intensity if they can be assembled into ordered monolayers. A three-phase self-assembly method is presented that successfully results in ordered Au NP monolayers for particle diameters ranging from 13 to 90 nm. The monolayer structure and Raman enhancement factors (EFs) are reported for a model analyte, rhodamine, as well as the best performing polymer electrolyte salt, lithium bis(trifluoromethane)sulfonimide. Experimental EFs for the most part correlate with predictions based on monolayer geometry and with numerical simulations that identify local electromagnetic field enhancements. The EFs for the best performing Au NP monolayer are between 106and 108and give quantitative signal response when analyte concentration is changed.
Aero-propulsion, Mechatronics, and Energy Center, Florida State University , Tallahassee, Florida 32310, United States.|The National High Magnetic Field Laboratory, Florida State University , Tallahassee, Florida 32310, United States.
Guang
G
Yang
Materials Science and Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
Jagjit
http://orcid.org/0000-0002-6875-0057
J
Nanda
Aero-propulsion, Mechatronics, and Energy Center, Florida State University , Tallahassee, Florida 32310, United States.
Boya
B
Wang
Aero-propulsion, Mechatronics, and Energy Center, Florida State University , Tallahassee, Florida 32310, United States.
Gang
G
Chen
Aero-propulsion, Mechatronics, and Energy Center, Florida State University , Tallahassee, Florida 32310, United States.|The National High Magnetic Field Laboratory, Florida State University , Tallahassee, Florida 32310, United States.
Daniel T
http://orcid.org/0000-0002-3819-0992
DT
Hallinan
FDTD; battery electrolyte; gold nanoparticle; monolayer; self-assembly; surface-enhanced Raman spectroscopy