基于光子晶体带边效应的表面增强拉曼基底

将光子晶体的带边效应与金纳米粒子的拉曼散射增强作用相结合,制备了一种新型光子晶体表面增强拉曼散射基底(PC-AuNPs),利用罗丹明B(RhB)作为报告分子,对所得基底性能进行检测.PC-AuNPs基底的制备包括3个步骤:在SiO2微球表面修饰氨基,再通过垂直沉降自组装得到蛋白石结构光子晶体(PC), 最后, 在光子晶体表面负载金纳米粒子(AuNPs).结果表明,光子晶体的带隙范围及AuNPs的负载量直接影响了PC-AuNPs基底的检测效果;以所得的PC-AuNPs基底测定RhB分子,其拉曼散射特征峰强度与浓度对数值呈现良好的线性关系,线性方程为I=1711lgRhB(mol/L)]+15244,线性相关系数R2=0.9994,检出限为1×10-8 mol/L,表明此PC-AuNPs基底可用于目标物的定性及定量检测.本方法提高了传统拉曼散射光谱检测灵敏度,操作简单,具有良好的重现性,可为其它新型检测基底的制备提供.

Surface Enhanced Raman Scattering Substrate Base onBand Gap Edge Effect of Photonic Crystal

In this work, band gap edge effect of photonic crystal (PC) was combined with gold nanoparticles (AuNPs) to fabricate a novel surface enhanced Raman scattering (SERS) substrate (PC-AuNPs).The preparation of PC-AuNPs substrate consisted of three steps.Firstly, SiO2 nanospheres were amino-modified.Then, an opal PC structure was obtained by vertical deposition of SiO2 nanospheres.Finally, AuNPs were loaded on the surface of opal structure.The Raman scattering signal of Rhodamine B (RhB) was detected on PC-AuNPs to evaluate the merits of this new substrate.It was found that the band gap range of photonic crystal and the loading amount of AuNPs were important factors for PC-AuNPs.A good linearity relationship could be obtained between the characteristic peak intensity of RhB and its logarithmic concentration (I=1711lgRhB (mol/L)]+15244, R2=0.9994).The detection limit reached 1×10-8 mol/L.This method was simple and exhibited good sensitivity and reproducibility for Raman scattering detection, and could provide a novel strategy for the development of SERS substrate.