Guerrini Luca, Izquierdo-Lorenzo Irene, Garcia-Ramos José V, Domingo Concepción, Sanchez-Cortes Santiago
Instituto de Estructura de la Materia, CSIC. Serrano, 121, 28006-Madrid, Spain.
Phys Chem Chem Phys. 2009 Sep 14;11(34):7363-71. doi: 10.1039/b904631c. Epub 2009 Jul 28.
The adsorption and self-assembly of alpha,omega-aliphatic diamines on silver nanoparticles is studied in this work by surface-enhanced Raman scattering (SERS) spectroscopy and plasmon resonance. These bifunctional diamines can act as linkers of metal nanoparticles (NPs) inducing the formation of hot spots (HS), i.e. interparticle junctions or gaps between metal NPs, which are points where a huge intensification of the electromagnetic field occurs. In addition, the dicationic nature of these diamines leads to the formation of cavities just at the induced hot spots which can be applied to molecular recognition of analytes. The influence of the surface coverage and the aliphatic chain length in diamines on their self-assembly was tested by the vibrational spectra and correlated to the different plasmon resonances of the dimers detected in the extinction spectra. These factors can be used for tuning the plasmon resonance of dimers formed by two metal nanoparticles where interparticle hot spots are formed. Finally, the analytical potential of these functionalized Ag nanoparticles is demonstrated for the trace detection of the pesticide aldrin.
本工作通过表面增强拉曼散射（SERS）光谱和等离子体共振研究了α,ω-脂肪族二胺在银纳米颗粒上的吸附和自组装。这些双功能二胺可作为金属纳米颗粒（NPs）的连接体，诱导热点（HS）的形成，即金属NPs之间的颗粒间连接或间隙，这些点会出现电磁场的巨大增强。此外，这些二胺的双阳离子性质导致仅在诱导的热点处形成空腔，可用于分析物的分子识别。通过振动光谱测试了二胺中表面覆盖率和脂肪族链长度对其自组装的影响，并与在消光光谱中检测到的二聚体的不同等离子体共振相关联。这些因素可用于调节由两个形成颗粒间热点的金属纳米颗粒形成的二聚体的等离子体共振。最后，证明了这些功能化银纳米颗粒在痕量检测农药艾氏剂方面的分析潜力。
