Shiraishi Yasuhiro, Shirakawa Eri, Tanaka Kazuya, Sakamoto Hirokatsu, Ichikawa Satoshi, Hirai Takayuki
Research Center for Solar Energy Chemistry and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , Toyonaka 560-8531, Japan.
ACS Appl Mater Interfaces. 2014 May 28;6(10):7554-62. doi: 10.1021/am5009002. Epub 2014 Apr 30.
UV or visible light irradiation of gold nanoparticles (AuNPs) modified with a thiol-terminated spiropyran dye promotes reversible aggregation or dispersion of AuNPs. This is facilitated by the electrostatic repulsion/attraction between the AuNPs controlled by the ring-opening/closing photoisomerization of the surface dyes. This photochemical method successfully produces aggregates of AuNPs with tunable sizes (20-340 nm) and narrow size distributions (standard deviation <34%) in a reversible manner. In addition, the formed aggregates, even when left in the dark condition, scarcely change their sizes because the stacking interaction between the ring-opened forms of surface dyes suppresses thermal reverse isomerization and maintains the attractive force between the AuNPs.
用硫醇封端的螺吡喃染料修饰的金纳米颗粒（AuNP）经紫外线或可见光照射后，可促进AuNP的可逆聚集或分散。表面染料的开环/闭环光异构化控制着AuNP之间的静电排斥/吸引，从而推动了这一过程。这种光化学方法成功地以可逆方式制备出了尺寸可调（20 - 340纳米）且尺寸分布窄（标准偏差<34%）的AuNP聚集体。此外，即使在黑暗条件下，所形成的聚集体尺寸也几乎不变，这是因为表面染料开环形式之间的堆积相互作用抑制了热逆向异构化，并维持了AuNP之间的吸引力。
