Liu Fanxin, Tang Chaojun, Zhan Peng, Chen Zhuo, Ma Hongtao, Wang Zhenlin
1] National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, PR China [2] Department of Applied Physics, Zhejiang University of Technology, Xiaoheshan, Hangzhou 310023, PR China.
Department of Applied Physics, Zhejiang University of Technology, Xiaoheshan, Hangzhou 310023, PR China.
Sci Rep. 2014 Mar 28;4:4494. doi: 10.1038/srep04494.
We have demonstrated the plasmonic characteristics of an ultrathin tetrahedral amorphous carbon (ta-C) film coated with Ag nanoparticles. The simulation result shows that, under resonant and non-resonant excitations, the strongest plasmonic electric field of 1 nm ta-C coated Ag nanoparticle is not trapped within the ta-C layer but is released to its outside surface, while leaving the weaker electric field inside ta-C layer. Moreover, this outside plasmonic field shows higher intensity than that of uncoated Ag nanoparticle, which is closely dependent on the excitation wavelength and size of Ag particles. These observations are supported by the SERS measurements. We expect that the ability for ultrathin ta-C coated Ag nanoparticles as the SERS substrates to detect low concentrations of target biomolecules opens the door to the applications where it can be used as a detection tool for integrated, on-chip devices.
我们已经展示了涂覆有银纳米颗粒的超薄四面体非晶碳（ta-C）薄膜的等离子体特性。模拟结果表明，在共振和非共振激发下，1纳米厚的涂覆有ta-C的银纳米颗粒的最强等离子体电场并非局限于ta-C层内，而是释放到其外表面，同时ta-C层内部留下较弱的电场。此外，这种外表面等离子体场的强度高于未涂覆银纳米颗粒的强度，这紧密依赖于银颗粒的激发波长和尺寸。这些观察结果得到了表面增强拉曼光谱（SERS）测量的支持。我们期望，超薄ta-C涂覆的银纳米颗粒作为SERS底物检测低浓度目标生物分子的能力，为其作为集成片上器件的检测工具的应用打开了大门。
