Reversible changes in the orientation of gold nanorod arrays on polymer brushes.

Yu Sekizawa,Yusuke Yonamine,Hideyuki Mitomo,Akinori Kuzuya,Kuniharu Ijiro,Mizuki Nihei,Takehiko Wada,Satoshi Nakamura

doi:10.1039/d0na00315h

Abstract

Nanoparticles exhibit a number of unique properties such as localized surface plasmon resonance (LSPR). As this LSPR is sensitive to geometrical or spatial conditions, the arrangement of nanoparticles, in particular the active arrangement of plasmonic structures, is an important issue. In this study, gold nanorod (GNR) arrays were prepared by GNR attachment on anionic polymer (DNA) brushes via electrostatic interactions and their stimuli-responsive changes in orientation were investigated. As a result, the orientation of GNR arrays on DNA brushes reversibly changed by the modulation of electrostatic interactions between GNRs and polymers via changes in the solution pH. As these extensive GNR arrays are prepared via easy bottom-up processes, GNR surface properties are easily tuned by simple modification, and DNAs could be replaced with various synthetic polymers, we believe that this study will lead to the development of next-generation materials and devices with actively tunable structures.

Highlights

Yu Sekizawa,‡a Hideyuki Mitomo, ‡*bc Mizuki Nihei,d Satoshi Nakamura,§e Yusuke Yonamine, bc Akinori Kuzuya, f Takehiko Wadag and Kuniharu Ijiro*bc
As these extensive gold nanorod (GNR) arrays are prepared via easy bottom-up processes, GNR surface properties are tuned by simple modification, and DNAs could be replaced with various synthetic polymers, aGraduate School of Life Sciences, Hokkaido University, Kita 10, Nishi 8, Kita-Ku, Sapporo 060-0810, Japan bResearch Institute for Electronic Science, Hokkaido University, Kita 21, Nishi 10, KitaKu, Sapporo 001-0021, Japan
We found that GNRs formed vertically aligned arrays when mildly cationized GNRs, which were modi ed with 20% cationic and 80% nonionic ligands, were attached on negatively charged polymer (DNA) brushes via moderate electrostatic interactions

Summary

Introduction

Yu Sekizawa,‡a Hideyuki Mitomo, ‡*bc Mizuki Nihei,d Satoshi Nakamura,§e Yusuke Yonamine, bc Akinori Kuzuya, f Takehiko Wadag and Kuniharu Ijiro*bc. COMMUNICATION Hideyuki Mitomo, Kuniharu Ijiro et al Reversible changes in the orientation of gold nanorod arrays on polymer brushes

Results

Conclusion