Porous Au Nanoparticles with Tunable Plasmon Resonances and Intense Field Enhancements for Single-Particle SERS.
Porous Au nanoparticles with fine-controlled overall particle sizes have been fabricated using a kinetically controlled seed-mediated growth method. In contrast to spherical Au nanoparticles with smooth surfaces, the porous Au nanoparticles exhibit far greater size-dependent plasmonic tunability and significantly intensified local electric field enhancements exploitable for single-particle plasmon-enhanced spectroscopies. The effects of the nanoscale porosity on the far- and near-field optical properties of the nanoparticles have been investigated both experimentally by optical extinction and single-nanoparticle Raman spectroscopic measurements and theoretically through finite-difference time-domain calculations.
†Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, United States.
Qingfeng
Q
Zhang
‡Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States.
Nicolas
N
Large
‡Department of Physics and Astronomy, Department of Electrical and Computer Engineering, and Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States.
Peter
P
Nordlander
†Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, United States.
Hui
H
Wang
finite-difference time-domain; nanoparticle; nanoporosity; plasmon resonance; seed-mediate growth; surface-enhanced Raman spectroscopy