摘要
金纳米星是一种具有尖状结构的多分枝纳米颗粒.为了使金纳米星枝杈长度可控,利用HEPES作为体系的还原剂、稳定剂及形状诱导剂,在制备过程中进行光辐照,得到的金纳米星枝杈长度比无光辐照时的金纳米星枝杈长度短,而且不同波长光辐照得到的金纳米星枝杈长度有显著不同.在此基础上,分析了金纳米星枝杈长度变化的物理过程,提出光诱导金纳米星生长过程中枝杈长度变化的理论模型.测量了不同枝杈长度的金纳米星在光辐照下一定时间内的温度变化,计算了金纳米星的光热转换效率.实验结果表明,光辐照制备金纳米星能够精确控制金纳米星枝杈长度范围,从而调控金纳米星的光热转换效率.
Gold nanostars are multi-branched nanoparticles with tip structures.Nanostars have excellent photoelectric properties,which make them able to be used in a variety of optoelectronics devices.Moreover,these stars have good biocompatibility and low toxicity,which opens broad application prospect in the biomedical field.Gold nanostars with admirable optical as well as thermal properties,are thought as a good candidate in cancer treatment that is a hot research topic in recent years.Gold nanostars with different branch-lengths were prepared by the photo-assisted method,and the effect of light was well studied in relation with gold nanostar branch-length.In the solution system,HEPES was used as the reducing agent,stable agent and shape-inducing agent.Under light irradiation,a certain amount of chloroauric acid solution（HAuCl_4） was added to the HEPES solution.After a period of time,gold nanostars were prepared.Different wavelengths of irradiating light were selected in this experiment.The wavelength has different effects on the growth of branches associated with gold nanostars.The transmission electron microscope and the ultraviolet-visible-near infrared spectrophotometer were used to analyze the morphology and absorption spectra of gold nanostars.Meanwhile,a nanomeasurer software was used to determine branch-lengths of gold nanostars under light irradiation of different wavelengths.The results indicate that the branches of the nanostars under irradiation were shorter than those of nanostars without irradiation.Different branch lengths correspond to different irradiation wavelengths.Based on these results,the physical process of shortening nanostars branches was analyzed,and a theoretical model of changing branch-length in the process of light-induced nanostars growth was proposed.The model indicates that there are two steps when the branch-length is changing.Firstly,the branch-length grows longer with the overall growth of the nanostar.Secondly,the nanostar becomes shorter because of the insatiability of HEPES mol
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2017年第8期229-236,共8页
Acta Physica Sinica
基金
国家自然科学基金(批准号:51475014)资助的课题~~
关键词
金纳米星
光辐照
枝权长度
光热转换效率
gold nanostars
light irradiation
branch length
photothermal conversion efficiency
