CAJ | 학술논문

借助水／油两相界面自组装形成致密排列且有序稳定的Au＠ SiO2单层膜，通过膜层层转移到固相基底的方法制备了具有不同纳米粒子层数的SERS基底，成功在同一硅片上制备了六层Au＠ SiO2纳米粒子膜，研究了不同膜层数与SERS信号的关系，结合SERS成像技术可测定纳米粒子膜在基底上的层数。通过改变探针分子在多层纳米粒子膜上的位置，研究了纳米粒子膜间的耦合增强效应。研究表明，同一层膜表面探针分子的SERS信号分布均匀，随膜层数的增加，SERS信号明显增强，当膜层达到第五层时探针分子的SERS信号最强，之后几乎保持不变，说明SERS信号主要来源于表层的五层纳米粒子膜，位于五层以下纳米粒子对SERS效应并没有贡献。固定探针分子仅吸附于底层纳米粒子表面，当再覆盖一层裸露纳米粒子膜后，SERS信号达到最大，其主要源于热点的增强作用占主导地位，而覆盖至第三层时，SERS信号反而出现微小减弱，这是由于多层的Au＠ SiO2纳米粒子膜影响了激发光以及信号的传播，但粒子间产生的耦合效应仍对底层的探针分子起增强作用，当覆盖至五层Au＠ SiO2膜后，探针分子SERS信号完全消失，由此说明纳米粒子单层膜控制在三层以内可有效检测底层及以上所有纳米粒子上吸附分子的SERS信号，该结果为制备理想SERS基底提供了实验依据。
차조수／유량상계면자조장형성치밀배렬차유서은정적Au＠ SiO2단층막，통과막층층전이도고상기저적방법제비료구유불동납미입자층수적SERS기저，성공재동일규편상제비료륙층Au＠ SiO2납미입자막，연구료불동막층수여SERS신호적관계，결합SERS성상기술가측정납미입자막재기저상적층수。통과개변탐침분자재다층납미입자막상적위치，연구료납미입자막간적우합증강효응。연구표명，동일층막표면탐침분자적SERS신호분포균균，수막층수적증가，SERS신호명현증강，당막층체도제오층시탐침분자적SERS신호최강，지후궤호보지불변，설명SERS신호주요래원우표층적오층납미입자막，위우오층이하납미입자대SERS효응병몰유공헌。고정탐침분자부흡부우저층납미입자표면，당재복개일층라로납미입자막후，SERS신호체도최대，기주요원우열점적증강작용점주도지위，이복개지제삼층시，SERS신호반이출현미소감약，저시유우다층적Au＠ SiO2납미입자막영향료격발광이급신호적전파，단입자간산생적우합효응잉대저층적탐침분자기증강작용，당복개지오층Au＠ SiO2막후，탐침분자SERS신호완전소실，유차설명납미입자단층막공제재삼층이내가유효검측저층급이상소유납미입자상흡부분자적SERS신호，해결과위제비이상SERS기저제공료실험의거。
The SiO2 shell with the thickness of 4 nm was attached onto high surface enhanced Raman spectroscopy (SERS) active Au core nanoparticles to obtain Au@ SiO2 core shell nanoparticles by the hydrolysis of sodium silicate solution with the boiling water bath .The inert shell of SiO2 isolated the direct interaction of Au nanoparticles and probe molecules .The stable ,compact and uniform monolayer nanoparticles film was self assembled at water/oil interface ,and one to six monolayers film was trans-ferred to Si wafer as SERS substrates through layer by layer technique .The relationship between the SERS activities and layers of the monolayer nanoparticles film on Si surface was investigated .The SERS mapping was developed to determine the layers of the Au@ SiO2 film .The coupling effect among the Au@ SiO2 films was explored by changing the adsorption location of the probe on the multilayer films .The result revealed that the monolayer film was a favourable candidate with high-quality performances for the SERS application .The SERS signal was distributed on the surface with high uniformity at the same monolayer film ,and it was enhanced in the intensity with the increase in film layers .It reached the maximun intensity as the film was over five lay-ers .It indicated that the SERS signal was contributed mainly by the first five monolayers .The probe molecules were immobilized onto the first monolayer nanoparticles film ,and the SERS signal from the probe approached to the maximum as the second mono-layer covered the probe modified first nanoparticles film .It was dominated by the coupling effect (“hot spots”) of the adjacent layers .The SERS signal decreased in intensity when the third layer was transferred onto the second layer ,and it disappeared af-ter the fouth layer was covered ,mainly duo to the shield of the nanoparticles film to the incident laser and Raman signal .The preliminary results provided guidance for fabricating optimal SERS substrates .