双金属双硅层核-壳纳米结构Au@SiO2@Ag@SiO2用于葡萄糖检测

制备了一种灵敏度高、 稳定性强的双金属双硅层核-壳结构纳米材料Au@SiO₂@Ag@SiO₂. 由于双金属之间的硅层促进了远程等离子体的激发转移, 使该纳米粒子具有良好的表面增强拉曼散射(SERS)的特性及优异的稳定性. 利用这种SERS活性材料能直接检测出人体尿液的主要成分, 且该材料呈现出对低浓度(10^-6 mol/L)葡萄糖的无标记高效检出能力. 此外, 还实现了人工尿液中等浓度(10^-3 mol/L)葡萄糖和尿素分子的同时检测, 以及实际尿液中10^-3 mol/L葡萄糖的检测. Au@SiO₂@Ag@SiO₂纳米粒子具有在多种生物分子存在时快速检测葡萄糖的实际应用潜力.

Bimetallic Multi-core Nanoparticles with Dual SiO2 Layer Au@SiO2@Ag@SiO2 for the Detection of Glucose†

Surface-enhanced Raman scattering(SERS) was demonstrated as a highly efficient approach for the amplification of extremely low signals due to the strong electromagnetic field enhancement that occurs near closely-packed metallic nanostructures, which was dependent on the unique localized surface plasmon resonance(LSPR). To develop sensitive SERS probes, different geometric configurations as approaches are focusing on the synthesis of advanced nanostructures, or efficient Raman label compounds that are resonant with excitation light. These geometric factors affect the polarization direction and magnitude of plasmonic coupling and the SERS signal intensity. As we know, plasmonic properties of Au and Ag NPs are highly sensitive to their shapes. In order to improve the performance of metal nanoparticles in SERS detection, we prepared a highly sensitive and stable bimetallic double silicon core-shell nanostructured material of Au@SiO₂@Ag@SiO₂. The nanoparticles have good Raman scattering properties and excellent stability, since the silicon layer between the bimetals promotes remote plasma excitation transfer. The main component of human urine can be directly detected by using this SERS active material, and the material exhibits the ability to detect highly effectiveness 10^-6 mol/L glucose with label-free Au@SiO₂@Ag@SiO₂ nanoparticles. In addition, simultaneous detection of medium concentrations of 10^-3 mol/L glucose and urea molecules in artificial urine and detection of 10^-3 mol/L glucose in actual urine were also achieved. The Au@SiO₂@Ag@SiO₂ nanoparticles show the potential for detection glucose in the presence of multiple biomolecules.