Light-Triggered Reversible Self-Assembly of Gold Nanoparticle Oligomers for Tunable SERS

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• 作者：Lei Zhang ; Liwei Dai ; Yun Rong ; Zhenzhong Liu ; Dingyi Tong ; Youju Huang ; Tao Chen
• 刊名：Langmuir
• 出版年：2015
• 出版时间：January 27, 2015
• 年：2015
• 卷：31
• 期：3
• 页码：1164-1171
• 全文大小：495K
• ISSN：1520-5827

文摘

A photoresponsive amphiphilic gold nanoparticle (AuNP) is achieved through the decoration of AuNP with hydrophilic poly(ethylene glycol) (PEG) and hydrophobic photoresponsive polymethacrylate containing spiropyran units (PSPMA). Owing to the photoresponsive property of spiropyran units, the amphiphilic AuNPs can easily achieve the controllable assembly/disassembly behaviors under the trigger by light. Under visible light, spiropyran units provide weak intermolecular interactions between neighbored AuNPs, leading to isolated AuNPs in the solution. While under UV light irradiation, spiropyran units in the polymer brushes transform into merocyanine isomer with conjugated structure and zwitterionic state, promoting the integration of adjacent AuNPs through 蟺鈥撓€ stacking and electrostatic attractions, further leading to the formation of Au oligomers. The smart reversible AuNP oligomers exhibited switchable plasmonic coupling for tuning surface-enhanced Raman scattering (SERS) activity, which is promising for the application of SERS based sensors and optical imaging.