Abstract

Silver nanoparticles decorated titania nanotube array (Ag-TiO₂ NTA) had been designed as active SERS substrate for a sensitive molecule detection. The Ag nanoparticles are deposited on the gaps and nanotube walls of the tubewall-separated TiO₂ NTA to form the independent Ag-TiO₂ NTA, alternatively on the nanotube wall surface of the tubewall-connected TiO₂ NTA to form the interconnected Ag-TiO₂ NTA. The microstructure of TiO₂ NTA is more critical to affect the SERS performance rather than the deposition cycles. The analytical enhancement factor was accordingly enhanced from 1.67 × 10⁵ for the interconnected Ag-TiO₂ NTA up to 9.44 × 10⁵ for the independent Ag-TiO₂ NTA. The microstructure-tailored and Ag deposition level-promoted Ag-TiO₂ NTA substrate achieved sensitive detection of 4-mercaptobenzoic acid. The superior SERS performance is caused by synergizing the localized electromagnetic field enhancement of Ag nanoparticles and the charge transfer chemical enhancement of TiO₂ NTA along with the light scattering enhancement of vertically aligned nanoarray architecture.

摘要

银纳米粒子装饰的二氧化钛纳米管阵列 (Ag-TiO ₂ NTA) 已被设计为用于敏感分子检测的活性 SERS 基板。Ag纳米粒子沉积在管壁分离的TiO ₂ NTA的间隙和纳米管壁上形成独立的Ag-TiO ₂ NTA，或者沉积在管壁连接的TiO ₂ NTA的纳米管壁表面上形成互连的Ag-TiO ₂ NTA。TiO ₂ NTA的微观结构对影响 SERS 性能比影响沉积循环更为关键。互连的 Ag-TiO ₂的分析增强因子相应地从 1.67 × 10 ⁵增强对于独立的 Ag-TiO ₂ NTA，NTA 高达 9.44 × 10 ⁵。微结构定制和Ag沉积水平促进的Ag-TiO ₂ NTA基板实现了4-巯基苯甲酸的灵敏检测。卓越的 SERS 性能是由 Ag 纳米粒子的局部电磁场增强和 TiO ₂ NTA的电荷转移化学增强以及垂直排列的纳米阵列结构的光散射增强协同作用引起的。