Huang Haowen, He Chaocai, Zeng Yunlong, Xia Xiaodong, Yu Xianyong, Yi Pinggui, Chen Zhong
School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, PR China.
J Colloid Interface Sci. 2008 Jun 1;322(1):136-42. doi: 10.1016/j.jcis.2008.03.004. Epub 2008 Mar 14.
A type of worm-like nanorods was successfully synthesized through conventional gold nanorods reacting with Na2S2O3 or Na2S. The generated worm-like gold nanorods comprise shrunk nanorod cores and enwrapped shells. Therefore, a gold-gold sulfide core-shell structure is formed in the process, distinguishing from their original counterparts. The formation of the gold chalcogenide layers was confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy. Experimental results showed that the thickness of the gold chalcogenide layers is controllable. Since the increase of shell thickness and decrease of gold nanorod core take place simultaneously, it allows one to tune the plasmon resonance of nanorods. Proper adjustment of reaction time, temperature, additives and other experimental conditions will produce worm-like gold nanorods demonstrating desired longitudinal plasmon wavelength (LPW) with narrow size distributions, only limited by properties of starting original gold nanorods. The approach presented herein is capable of selectively changing LPW of the gold nanorods. Additionally, the formed worm-like nanorods possess higher sensitive property in localized surface plasmon resonance than the original nanorods. Their special properties were characterized by spectroscopic methods such as Vis-NIR, fluorescence and resonance light scattering. These features imply that the gold nanorods have potential applications in biomolecular recognition study and biosensor fabrications.
通过传统的金纳米棒与Na2S2O3或Na2S反应，成功合成了一种蠕虫状纳米棒。生成的蠕虫状金纳米棒由收缩的纳米棒核和包裹的壳组成。因此，在此过程中形成了金-硫化金核壳结构，这与它们原来的对应物不同。通过透射电子显微镜和X射线光电子能谱证实了硫属化金层的形成。实验结果表明，硫属化金层的厚度是可控的。由于壳厚度的增加和金纳米棒核的减小同时发生，这使得人们能够调节纳米棒的等离子体共振。适当调整反应时间、温度、添加剂和其他实验条件，将产生具有所需纵向等离子体波长（LPW）且尺寸分布窄的蠕虫状金纳米棒，这仅受起始原始金纳米棒性质的限制。本文提出的方法能够选择性地改变金纳米棒的LPW。此外，形成的蠕虫状纳米棒在局部表面等离子体共振中比原始纳米棒具有更高的灵敏特性。它们的特殊性质通过可见-近红外、荧光和共振光散射等光谱方法进行了表征。这些特性表明金纳米棒在生物分子识别研究和生物传感器制造方面具有潜在应用。
