Abstract
Anisotropic gold nanoparticles often exhibit superior optical properties compared to spherical ones, in part due to intense electric field localization near sharp geometric features and a broadly tunable localized surface plasmon resonance. As a result, anisotropic nanoparticles are attractive building blocks for surface-enhanced Raman spectroscopy (SERS) substrates. To unlock the full potential of such substrates, one should be able to (1) generate a sufficient number of SERS hotspots with structures of controlled shape and size and (2) remove ligands so that analytes can easily access nanoparticle surface sites. Here, we develop a synthetic strategy for the shape- and size-controlled anisotropic growth of gold nanoparticles (concave rhombic dodecahedra and concave cubes, 70-135 nm characteristic length) from spherical seeds anchored on a structurally complex surface (common filter paper) and subsequently combine electrodynamics and electronic structure calculations with experiment to systematically characterize these substrates using SERS. Furthermore, we explore the generalizable functionality of these substrate-stabilized nanoparticles by using a continuous extraction method to partially remove surface ligands that were necessary for anisotropic growth, enabling the specific SERS detection of serotonin, a molecular neurotransmitter with a weak affinity for gold.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2307-2314 |
| Number of pages | 8 |
| Journal | Journal of Physical Chemistry C |
| Volume | 122 |
| Issue number | 4 |
| DOIs | |
| State | Published - Feb 1 2018 |
Funding
This work was partially supported by the National Science Foundation’s MRSEC program (DMR-1121262) and made use of its Shared Facilities at the Materials Research Center of Northwestern University. This material is also based on research sponsored by the Air Force Research Laboratory under agreement number FA8650-15-2-5518. The U.S. Government is authorized to reproduce and distribute reprints for governmental purposes notwithstanding any copyright notation thereon. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Air Force Research Laboratory or the U.S. Government. M.J.A. and C.R.L. gratefully acknowledge support from the NSF Graduate Research Fellowship Program and the Patrick G. and Shirley W. Ryan Fellowship. M.B.R. gratefully acknowledges support from the NDSEG fellowship program. This work was partially supported by the National Science Foundation's MRSEC program (DMR-1121262) and made use of its Shared Facilities at the Materials Research Center of Northwestern University. This material is also based on research sponsored by the Air Force Research Laboratory under agreement number FA8650-15-2-5518. The U.S. Government is authorized to reproduce and distribute reprints for governmental purposes notwithstanding any copyright notation thereon. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Air Force Research Laboratory or the U.S. Government. M.J.A. and C.R.L. gratefully acknowledge support from the NSF Graduate Research Fellowship Program and the Patrick G. and Shirley W. Ryan Fellowship. M.B.R. gratefully acknowledges support from the NDSEG fellowship program.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Energy
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films