Three-Dimensional-Stacked Gold Nanoparticles with Sub-5 nm Gaps on Vertically Aligned TiO2 Nanosheets for Surface-Enhanced Raman Scattering Detection Down to 10 fM Scale
Three-Dimensional-Stacked Gold Nanoparticles with Sub-5 nm Gaps on Vertically Aligned TiO2 Nanosheets for Surface-Enhanced Raman Scattering Detection Down to 10 fM Scale
复制标题
垂直排列的 TiO2 纳米片上具有亚 5 nm 间隙的三维堆叠金纳米粒子，用于低至 10 fM 尺度的表面增强拉曼散射检测
DOI：
10.1021/acsami.8b11713
复制
发表时间：
2018
影响因子：
9.5
通讯作者：
Duan Huigao
中科院分区：
文献类型：
--
作者：
Wang Xuejiao;Zhu Xupeng;Shi Huimin;Chen Yiqin;Chen Zhiquan;Zeng Yixuan;Tang Zhixiang;Duan Huigao
寻找高灵敏度和低成本的基底是表面增强拉曼散射（Sers）技术实际应用的迫切需要。在这项工作中，我们报告了一个超灵敏的SERS活性基板的基础上，湿化学合成的垂直排列的大面积TiO 2纳米片（NS）装饰密集堆积的金纳米粒子（Au NPs）与次5 nm的间隙。通过多步连续沉积工艺，三维堆叠的Au NPs被3 nm的SiO2层夹在中间组装到TiO 2 NS上，由于形成了超微小等离子体间隙和半导体/金属界面，从而实现了许多热点。实验结果表明，以结晶紫为探针分子，在不发生任何凝聚过程的情况下，所制备的基底显示出低至10 fM（10- 14 M）的检测限。控制实验和电磁模拟表明，由3 nm的间隔定义的纳米间隙是必不可少的获得优异的Sers性能。利用其超灵敏的检测能力，我们证明了所制备的Sers基底可用于牛奶中三聚氰胺的痕量分析。
Seeking for ultrasensitive and low-cost substrates is highly demandable for practical applications of surface-enhanced Raman scattering (SERS) technology. In this work, we report an ultrasensitive SERS-active substrate based on wet-chemistry-synthesized vertically aligned large-area TiO2nanosheets (NSs) decorated by densely packed gold nanoparticles (Au NPs) with sub-5 nm gaps. Via a multistep successive deposition process, three-dimensional-stacked Au NPs sandwiched by a 3 nm SiO2layer were assembled onto the TiO2NS, enabling numerous hotspots due to the formation of both ultratiny plasmonic gaps and semiconductor/metal interfaces. Experimental results show that the fabricated substrate displays a detection limit down to 10 fM (10–14M) without involving any condensation process by using the crystal violet as probe molecules. Control experiments and electromagnetic simulations indicate that the nanogaps defined by the 3 nm spacer are essential for the obtained excellent SERS performance. With its ultrasensitive detection capability, we demonstrate that the fabricated SERS substrate can be used for the trace analysis of melamine in milk.