TY - JOUR
T1 - Reversible tuning of plasmon coupling in gold nanoparticle chains using ultrathin responsive polymer film
AU - Nergiz, Saide Z.
AU - Singamaneni, Srikanth
PY - 2011/4/27
Y1 - 2011/4/27
N2 - We demonstrate large and reversible tuning of plasmonic properties of gold nanoparticles mediated by the reversible breaking and making of linear and branched chains of gold nanoparticles adsorbed on an ultrathin (1 nm) responsive polymer film. Atomic force microscopy revealed that at pH below the isoelectric point of the polybase (extended state of the polymer chains), gold nanoparticles adsorbed on the polymer layer existed primarily as individual nanoparticles. On the other hand, at higher pH, the polymer chains transition from coil to globule (collapsed) state, resulting in the formation of linear and branched chains with strong interparticle plasmon coupling. Reversible aggregation of the nanoparticles resulted in large and reversible change in the optical properties of the metal nanostructure assemblies. In particular, we observed a large redistribution of the intensity between the individual and coupled plasmon bands and a large shift (nearly 95 nm) in the coupled plasmon band with change in pH. Large tunability of plasmonic properties of the metal nanostructure chains reported here is believed to be caused by the chain aggregates of nanoparticles and un-cross-linked state of the adsorbed polymer enabling large changes in polymer chain conformation.
AB - We demonstrate large and reversible tuning of plasmonic properties of gold nanoparticles mediated by the reversible breaking and making of linear and branched chains of gold nanoparticles adsorbed on an ultrathin (1 nm) responsive polymer film. Atomic force microscopy revealed that at pH below the isoelectric point of the polybase (extended state of the polymer chains), gold nanoparticles adsorbed on the polymer layer existed primarily as individual nanoparticles. On the other hand, at higher pH, the polymer chains transition from coil to globule (collapsed) state, resulting in the formation of linear and branched chains with strong interparticle plasmon coupling. Reversible aggregation of the nanoparticles resulted in large and reversible change in the optical properties of the metal nanostructure assemblies. In particular, we observed a large redistribution of the intensity between the individual and coupled plasmon bands and a large shift (nearly 95 nm) in the coupled plasmon band with change in pH. Large tunability of plasmonic properties of the metal nanostructure chains reported here is believed to be caused by the chain aggregates of nanoparticles and un-cross-linked state of the adsorbed polymer enabling large changes in polymer chain conformation.
KW - gold nanoparticles
KW - localized surface plasmon resonance
KW - nanoparticle chains
KW - responsive plasmonics
KW - responsive polymer
UR - http://www.scopus.com/inward/record.url?scp=79957813369&partnerID=8YFLogxK
U2 - 10.1021/am200109r
DO - 10.1021/am200109r
M3 - Article
AN - SCOPUS:79957813369
SN - 1944-8244
VL - 3
SP - 945
EP - 951
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 4
ER -