title: Plasmonic nanoparticle networks formed using iron porphyrin molecular bridges.
abstract: The adsorption orientation of the iron(III) tetrakis(1-methyl-4-pyridyl)porphine (FeTMPyP) μ-oxo-bridged dimer species located in the inter-particle gap of solid gold nanosphere (SGN) and hollow gold nanosphere (HGN) networks was studied using a combination of linear extinction and surface-enhanced Raman Scattering (SERS) measurements. Nanoparticle aggregation was accomplished by μM additions of iron porphyrin to the colloidal SGN and HGN solutions. Aggregation was monitored by measuring the UV-Visible-NIR extinction spectra of the nanoparticle systems; a broadened and red-shifted localized surface plasmon resonance (LSPR), relative to the LSPR of the isolated nanoparticles, indicated aggregate formation. In conjunction with the LSPR extinction measurements, wavelength-dependent SERS measurements were used to determine the orientation of the FeTMPyP with respect to the SGN and HGN surfaces.
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4390, USA.
authors.forename: Lenzi J
authors.initials: LJ
authors.lastname: Williams
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Dowgiallo
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Knappenberger