Alternating Plasmonic Nanoparticle Heterochains Made by Polymerase Chain Reaction and Their Optical Properties.
Organization of nanoparticles (NPs) of different materials into superstructures of higher complexity represents a key challenge in nanotechnology. Polymerase chain reaction (PCR) was used in this study to fabricate chains consisting of plasmonic NPs of different sizes, thus denoted heterochains. The NPs in such chains are connected by DNA oligomers, alternating in a sequence big-small-big-small-... and spanning lengths in the range of 40-300 nm by varying the number of PCR cycles. They display strong plasmonic chirality at 500-600 nm, the chiral activity revealing nonmonotonous dependence on the length of heterochains. We find the strength of surface-enhanced Raman scattering (SERS) to increase with chain length, while the chiral response initially increased and then decreased with the number of PCR cycles. The relationship between the optical properties of the heterochains and their structure/length is discussed. The length-dependent intense optical response of the plasmonic NP heterochains holds great potential for biosensing applications.
Yuan
Y
Zhao
Liguang
L
Xu
‡BioNanoPlasmonics Laboratory, CIC biomaGUNE, Paseo de Miramón 182, Donostia - San Sebastian 20009, Spain.|§Ikerbasque, Basque Foundation for Science, Bilbao 48011, Spain.
Luis M
LM
Liz-Marzán
Hua
H
Kuang
Wei
W
Ma
∥IQFR-CSIC, Serrano 119, 28006 Madrid, Spain.
Ana
A
Asenjo-Garcı́a
∥IQFR-CSIC, Serrano 119, 28006 Madrid, Spain.
F Javier
FJ
García de Abajo
⊥Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan, 48109, United States.
Nicholas A
NA
Kotov
Libing
L
Wang
Chuanlai
C
Xu
SERS; assembly; gold nanoparticles; heterochains; plasmonic chirality; polymerase chain reaction