title: Gold nanorods as plasmonic nanotransducers: distance-dependent refractive index sensitivity.
abstract: Owing to the facile tunability of the localized surface plasmon resonance wavelength (LSPR) and large refractive index sensitivity, gold nanorods (AuNR) are of high interest as plasmonic nanotransducers for label-free biological sensing. We investigate the influence of gold nanorod dimensions on distance-dependent LSPR sensitivity and electromagnetic (EM) decay length using electrostatic layer-by-layer (LbL) assembly of polyelectrolytes. The electromagnetic decay length was found to increase linearly with both nanorod length and diameter, although to variable degrees. The rate of EM decay length increase with nanorod diameter is significantly higher compared to that of the length, indicating that diameter is a convenient handle to tune the EM decay length of gold nanorods. The ability to precisely measure the EM decay length of nanostructures enables the rational selection of plasmonic nanotransducer dimensions for the particular biosensing application.
authors.affiliation: Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri 63130, United States.
authors.forename: Limei
authors.initials: L
authors.lastname: Tian
authors.forename: Enze
authors.initials: E
authors.lastname: Chen
authors.forename: Naveen
authors.initials: N
authors.lastname: Gandra
authors.forename: Abdennour
authors.initials: A
authors.lastname: Abbas
authors.forename: Srikanth
authors.initials: S
authors.lastname: Singamaneni
mesh_terms: D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D006046:Gold