Alternating Plasmonic Nanoparticle Heterochains Made by Polymerase Chain Reaction and Their Optical Properties
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- 作者：Yuan Zhao ; Liguang Xu ; Luis M. Liz-Marz谩n ; Hua Kuang ; Wei Ma ; Ana Asenjo-Garcı ; ́ ; a ; F. Javier Garc铆a de Abajo ; Nicholas A. Kotov ; Libing Wang ; Chuanlai Xu
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2013
- 出版时间：February 21, 2013
- 年：2013
- 卷：4
- 期：4
- 页码：641-647
- 全文大小：415K
- 年卷期：v.4,no.4(February 21, 2013)
- ISSN：1948-7185
文摘
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鈥搒mall鈥揵ig鈥搒mall鈥?.. and spanning lengths in the range of 40鈥?00 nm by varying the number of PCR cycles. They display strong plasmonic chirality at 500鈥?00 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.