作者：Baoqing Liu, XF Lu, Z Qiao, LP Song, Q Cheng, JW Zhang, Afang Zhang*, Youju Huang, and Tao Chen*
关键字：stimulus responsive, Gold NPs monolayer, Anticounterfeiting
论文来源：期刊
具体来源：Langmuir 2018, 34, 13047-13056
发表时间：2018年
Two-dimensional (2D) gold nanoparticle (Au NP) monolayer film possesses a lot of fascinating peculiarities, and has shown promising applications in photoelectrical devices, catalysis, spectroscopy, sensors, and anticounterfeiting. Because of the localized surface plasmon
resonance (LSPR) property predetermined by the natural structure of metal nanoparticles, it is usually difficult to realize the reversible LSPR transition of 2D film. In this work, we report on the fabrication of a large-area freestanding Au NP monolayer film with dual-responsive switchable plasmonic property using a pH- or thermal-responsive dendronized copolymer as a
stimuli-sensitive linker. In this system, an oligoethylene-glycol-based (OEGbased) dendronized copolymer (named PG1A) with pH or temperature sensitivity was first modified onto the surface of a Au NP. Then, polyethylene glycol dibenzyl aldehyde (PEG-DA) was introduced to
interact with the amino moieties from PG1A before the process of oil?water interfacial self-assembly of NPs, resulting in an elastic, robust, pH- or temperature-sensitive interpenetrating network among Au NPs in monolayer films. In addition, the film could exhibit reversibly plasmonic shifts of about 77 nm and inherent color changes through varying temperature or pH. The obtained free-standing monolayer film also shows an excellent transferable property, which can be easily transferred onto substrates such as plastic molds, PDMS, copper grids, and silicon wafers. In virtue of these peculiarities of the free-standing property, special plasmonic signal, and homologous macroscopic color, the transferred film was primely applied to an anticounterfeiting security label with clear color change at the designed spots, providing a new avenue to plasmonic nanodevices with various applications.