有序介孔碳负载纳米金属颗粒及其SERS性能研究

Fabrication and SERS Performance of Ordered Mesoporous Carbon⁃supported Metal Nanoparticles

为了提高待测物的表面增强拉曼散射光谱(SERS)的检测性能,采用超声技术在有序介孔碳(OMC)上负载Ag和Au纳米颗粒(NPs)制备出OMC/Ag@Au NPs复合材料并以其作为SERS检测基底。通过TEM、SEM和XRD等技术对材料进行结构表征,以罗丹明6G(R6G)为探针分子,对材料的SERS检测性能进行评价。研究结果表明,OMC/Ag@Au NPs复合材料的孔径为5.9 nm,比表面积高,为426.1 m^(2)·g^(-1),对有机物分子表现出较强的吸附富集作用,R6G的检测限达到10-8 mol/L,拉曼位移在613 cm^(-1)处峰值强度的相对标准偏差(RSD)为3.7%,且该复合材料在室温条件下储存45 d后仍能保持高SERS活性。由此可见,采用超声技术制备OMC/Ag@Au NPs复合材料的方法简便,复合材料的SERS检测灵敏度高、均一性和稳定性好。这是由于:一方面,Ag和Au NPs的表面等离子体共振效应(SPR)产生电磁增强作用;另一方面,OMC对R6G分子的吸附作用产生化学增强作用。该复合材料在有机物检测领域具有很大的应用潜力。

To improve the performance of surface⁃enhanced Raman scattering(SERS),Ag and Au nanoparticles(NPs)were loaded on the surface of ordered mesoporous carbon(OMC)using an ultrasonic technique.The microstructure was characterized through TEM,SEM and XRD techniques.And R6G were used as probe molecules to evaluate the SERS performance of OMC/Ag@Au NPs composite.The pore size and sur⁃face area of OMC/Ag@Au NPs composite were 5.9 nm and 426.1 m^(2)·g^(-1),which exhibits great ability of enrichment for organic molecules.The detection limit of R6G is determined to be as low as 10-8 mol/L.Furthermore,the RSD of the peak intensity at 613 cm^(-1)is 3.7%,and it remained high SERS activity stored over 45 days under ambient condition.Through a simple and low⁃cost ultrasonic technique,we prepared OMC/Ag@Au NPs composite which exhibits high SERS activity,reproducibility and stability.The excellent SERS activity mainly stems from two distinct mechanisms,electromagnetic enhancement from surface plasmon resonance(SPR)of Ag NPs and Au NPs as well as chemical enhancement from absorption effect of OMC,indicating a great potential in detecting organic pollutants.