Herein, NaYF4:Yb,Tm@SiO2/carbon dot nanocomposites have been successfully fabricated by a facile route. The structure and morphology of the nanocomposites were characterized by SEM, TEM, XRD, FT-IR and XPS measurements. It was demonstrated that carbon dots were embedded well in the silica layer coating on the surface of NaYF4:Yb,Tm nanoparticles, leading to a relatively stable structure of the nanocomposites. The nanocomposites showed interesting dual-mode luminescence properties, i.e. blue green light under a 365 nm UV lamp and blue purple light under a 980 nm laser. They were utilized to achieve light conversion films, ion detection probes and cell imaging, suggesting their great potential in the fields of anti-counterfeiting and bioapplications.
Nanoporous gold (NPG) has been reported to provide remarkable fluorescence enhancement of adjacent fluorophores due to the metal-enhanced fluorescence phenomenon (MEF), and the enhancement is related with the characteristic length of nanoporosity. To fully understand the effect of NPG on nearby fluorophores, it is desirable to study systems with well-defined metal-fluorophore distances. In this study we investigated the distance effect by using silica as the spacing layer between fluorophores and NPG. Originating from competition between plasmonic amplifying and metallic quenching, the dye molecule rhodamine 6G was best enhanced by 20-nm SiO2 coated nanoporous gold with the pore size of 36 nm, while the protein phycoerythrin was best enhanced by 15-nm SiO2 coated nanoporous gold with the pore size of 42 nm and the quantum dots were best enhanced by 20-nm SiO2 coated nanoporous gold with the pore size of 42 nm.
Xi Xie,Xu Xu,Qixuan Zhu,Shaorong Lu,Yuqi Li,Yongkang Bai
Smart materials with reversible shape transformation have drawn enormous interest for their potential applications in various fields. Herein, we show a novel reversible shape change bilayer material based on a shape memory polymer layer and a passive silicone layer, which can exhibit excellent thermo- and near infrared (NIR) light-induced reversible multi-shape memory performance. The NIR light responsiveness of the material is achieved by the introduction of tannic acid/ferric ion coordination, while the multi-shape memory effect originated from the wide glass transition temperature of the shape memory polymer layer. Based on the shape recovery stress at elevated temperature and resilience force of the silicone layer during the cooling process, thermo- and NIR light-induced reversible multi-shape memory performance is realized. Moreover, the practicability of the bilayer material as a light-driven actuator and temperature sensor is also investigated, demonstrating its versatile application potential as an actuator and sensor.
危险品化学品经营许可证（带存储）