摘要
利用具有高密度拉曼热点的金属纳米结构作为表面增强拉曼散射(SERS)基底,可以显著增强吸附分子的拉曼信号.本文通过阳极氧化铝模板辅助电化学法沉积制备了高密度银(Ag)纳米颗粒阵列;利用扫描电子显微镜和反射谱表征了样品的结构形貌和表面等离激元特性;用1, 4-苯二硫醇(1, 4-BDT)为拉曼探针分子,研究了Ag纳米颗粒阵列的SERS效应.通过优化沉积时间,制备出高SERS探测灵敏度的Ag纳米颗粒阵列,检测极限可达10^(-13)mol/L;时域有限差分法模拟结果证实了纳米颗粒间存在强的等离激元耦合作用,且发现纳米颗粒底端的局域场增强更大.研究结果表明Ag纳米颗粒阵列可作为高效的SERS基底.
The Raman signal of adsorbed Raman probe molecule can be significantly enhanced by using metallic nanostructures with high-density hot spots as surface enhanced Raman scattering（SERS） substrates. A great effort has been devoted to the improving of the SERS detection sensitivity and reproducibility by preparing ordered metal nanostructure arrays with controlled particle size, shape and hot spot position, which are used as SERS substrates. In this paper, we prepare highdensity Ag nanoparticle arrays by electrochemical deposition in anodic aluminum oxide（AAO） templates. The particle size and the nanogap between the adjacent particles can be adjusted by changing the deposition time. The structures and surface plasmons of Ag nanoparticle arrays are characterized by scanning electron microscopy and reflectance spectra.The size of the gap between the particles significantly affects the plasmon resonance and the plasmon coupling between the particles. The SERS properties of Ag nanoparticle arrays are investigated by using 1, 4-benzenedithiol（1, 4-BDT）as Raman probe molecule. The Ag nanoparticle arrays with high SERS detection sensitivity and high reproducibility（uniformity） are prepared by optimizing the deposition time（the nanogap between the adjacent particles）, and the detection limit of the 1, 4-BDT can reach 10^（-13） mol/L. The relative standard deviation of the SERS signal intensity randomly measured from 20 spots on the Ag nanoparticle array substrate is 5.35%. The finite-difference time domain simulations confirm that the plasmon coupling between nanoparticles is strong, and that the coupling between the nanoparticles will increase as the nanogap decreases. Additionally, the local field is enhanced at the bottom of the nanoparticle and the gap between the Ag nanoparticle and the AAO template is larger. These results show that Ag nanoparticle array can be used as a high-efficiency SERS substrate.
作者
程自强
石海泉
余萍
刘志敏
Cheng Zi-Qiang;Shi Hai-Quan;Yu Ping;Liu Zhi-Min(Department of Applied Physics,School of Science,East China Jiaotong University Nanchang 330013,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第19期269-274,共6页
Acta Physica Sinica
基金
江西省教育厅基金项目(批准号:GJJ160532)
江西省"百人远航工程"人才项目(批准号:2017-91)
江西省青年教师出国访学项目(批准号:2016-109)资助的课题~~
