PDMS-Au复合基底上多环芳烃分子的表面增强拉曼光谱

利用聚二甲基硅氧烷(PDMS)对有机物的富集功能,通过在金纳米粒子单层膜(Au MLF)表面旋涂薄层PDMS膜制备PDMS-Au MLF复合表面增强拉曼光谱(SERS)基底.研究了SERS增强性能与旋涂液浓度及稀释溶剂间的关系,考察了复合基底增强活性的均匀性.研究发现,采用叔丁醇为稀释溶剂,浓度为2%(质量分数)的旋涂液时所得复合基底表面多环芳烃(PAHs)的SERS信号强度最高,且此基底SERS信号强度偏差小于10%.分别以PDMS-Au MLF复合材料和Au MLF作为基底,对比研究了对萘、蒽、菲和芘4种多环芳烃的SERS检测能力.结果表明,PDMS-Au MLF复合基底对以上4种有机物的检出限分别为10~(-6),10~(-7),10~(-8)及10~(-7)mol/L,相比于单一Au MLF基底,其检测限至少降低了1个数量级,这主要源自于PDMS对PAHs的富集作用,且此类复合基底可用于多种多环芳烃混合物的特征识别.

Surface Enhanced Raman Spectroscopic Investigation of PAHs at a PDMS-Au Composite Substrate

A composite surface enhanced Raman spectroscopy (SERS) substrate was fabricated through the spin coating of polydimethylsiloxane(PDMS) layer onto the Au nanoparticles monolayer film(Au MLF).This substrate exhibited the high uniformity with the derivation of SERS intensities less than 10％.Four kinds of PAHs (naphthalene,naphthalene,phenanthrene and pyrene) were employed as probe molecules to verify the performance of the composite SERS substrate.The results showed that the limit of detection(LOD) of naphthalene,anthracene,phenanthrene and pyrene detected by PDMS-Au composite substrate were 10-6,10-7,10-8 and 10-7 mol/L,respectively.By comparing to Au MLF substrate,the LODs were decreased by almost one order of magnitude.It was mainly originated from the physical enrichment of target molecules by the PDMS layers.Moreover,this approach opens a potential application in the identification of the mixture of PAHs.