胞嘧啶在沉积激光烧蚀Ag纳米颗粒电极上的SERS分析

Surface-Enhanced Raman Scatting of Cytosine on Silver Nanoparticles Electrode Modified with Pure Ag Colloids Produced by Laser Ablation

用Nd:YAG激光器在二次去离子水中烧蚀银片,制备出了尺度分布均匀、并且具有很好的稳定性的"化学纯净"的Ag胶体系,并在电化学体系中将这种银胶沉积在粗糙的银电极表面,研究了胞嘧啶分子吸附在沉积Ag纳米颗粒电极表面随电极电位改变的表面增强拉曼光谱(SERS)。分析表明:(1)沉积银纳米颗粒的电极将金属电极与金属溶胶体系各自的优势很好的结合起来,形成了一种高效的SERS活性基底。(2)胞嘧啶在沉积银颗粒的电极表面以N3位竖直吸附,并且随着电位的负移,大多数SERS峰的位置发生了红移,表明胞嘧啶在电极表面吸附作用减弱。

＇Chemically pure＇ Ag colloids were prepared by laser ablation of Ag plate in pure water.The Ag colloids have good stability and the Ag nanoparticles in the colloids have homogeneous size distribution.The roughened silver electrode modified with the ＇chemically pure＇ silver nanoparticles was used as a substrate.The high-quality SERS spectra and the potential-dependent SERS of cytosine were obtained.The results indicated that：（1）the silver-modified silver electrode was a highly SERS-active substrate;（2）cytosine adsorbed perpendicularly via the N3-end on the silver nanoparticles modified silver electrode,and most bands＇ frequencies red shift with the negative movement of the potential indicating that the adsorption interaction becomes weak.