Ag@SiO2纳米颗粒的制备及其在H2O2检测上的应用

利用柠檬酸三钠还原硝酸银制备了银纳米颗粒(AgNPs),然后通过氨水水解正硅酸乙酯(TEOS)的方法,在AgNPs上沉积SiO2,制备出以Ag为核,SiO2为壳的复合纳米颗粒(Ag@SiO2).调节TEOS用量,可以控制SiO2层的厚度.根据AgNPs的局域表面等离激元共振(LSPR)效应,将制得的Ag@SiO2颗粒用于H2O2的检测,检测下限为1μmol/L,并可以通过控制SiO2层的厚度方便地调节Ag@SiO2颗粒与H2O2反应的速率.与传统方法相比,具有简单、快速、成本低的优点.分别运用TEM、紫外-可见分光光度计对反应前后Ag@SiO2颗粒形貌及反应过程中其LSPR吸收的变化进行了表征.

Preparation of Ag@SiO2 Nanoparticles and Their Application in the Detection of H2O2

Silver nanoparticles (AgNPs) were prepared by reducing silver nitrate with trisodium citrate. By adjusting the amount of tetraethyl orthosilicate (TEOS), which can be hydrolyzed by ammonia, a SiO2 layer with different thicknesses was coated on AgNPs to produce Ag@SiO2 composites. Based on the localized surface plasmon resonance (LSPR) of AgNPs, Ag@SiO2 was employed in the detection of H202 with a detection limit of 1 μmol/L, where reaction rate was easily controlled by changing the thickness of the SiO2 layer. Compare with traditional methods, the method herein is very simple, rapid and low-cost. Transmission electron microscope (TEM) and UV-Vis spectrophotometer were used to characterize the shape and LSPR absorption of Ag@SiO2 respectively.