超疏水贵金属微纳多级结构SERS基底的构筑及三相界面催化过程的原位检测研究

Recently, Surface-enhanced Raman spectroscopy (SERS) technology has been applied in monitoring catalytic chemical reaction because of the ultrahigh sensitivity and specific molecular fingerprint information. To accurately realize monitoring and controlling surface-interface chemical reaction, novel SERS substrates and surface-interface construction are indispensable. In this project, we combine noble metal micro/nano-hierarchical structure with bio-inspired surface super-wettability for preparing superhydrophobic SERS substrates. Droplet detection method will be used forming gas-liquid-solid three-phase interface. By using the different contact mode with gas-solid/liquid-solid interfaces, coupling reaction process of nitro- and amino-compounds will be in situ detected and explore the surface plasmon catalyzed reaction mechanism in-depth. By using electrochemical deposition and other methods, Au/Ag micro/nano-structures with different morphologies would be prepared. By low surface energy modification, we will obtain superhydrophobic SERS substrate. The best preparing conditions can be determined by the substrates SERS performing. Surface plasmon catalyzed reaction will be real-time monitored at gas-liquid-solid three-phase interface by SERS with different substrates, wettability, laser power and reaction time. Regularities and catalytic reaction mechanism will be illustrated in the experiments by comparing with other contact modes. The work will offer research fundamental and new idea for SERS technology and surface plasmon catalyzed reaction in the future.

表面增强拉曼光谱(SERS)因其超灵敏优势和独特的分子指纹信息，近年来被用于检测分子间催化化学反应，成为研究热点。要实现监测及控制表界面化学反应过程，新型SERS活性基底及表界面的构筑益显重要。本项目将采用贵金属微纳米多级结构与表面仿生超浸润相结合，制备超疏水SERS基底；采用液滴直接检测法构筑气-液-固三相界面，利用其不同于传统气固、液固两相界面的特殊接触方式，原位监测氨基化合物/硝基化合物的偶联反应的发生过程，探究表面等离激元催化反应机理。利用电化学沉积、表面修饰等方法制备超疏水金银微纳米多级结构SERS基底，探索制备规律及最佳测试条件；在气-液-固三相界面处利用SERS技术对表面等离激元催化反应进行实时监测，探索基底形貌、浸润性、激光功率、反应时间等的影响，揭示催化反应规律，对比气固、液固两相接触模式验证催化反应机理，结合仿生思路深化SERS技术和表面等离激元催化的研究。

表面增强拉曼光谱（SERS）具有高检测灵敏度，近年来在单分子检测方面取得了大量的成果，尤其在表面等离激元催化反应研究中起到了重要的开拓作用。然而在表面等离激元催化反应的研究中，在气-液-固三相界面中还未进行广泛深入探究；由于在超疏水微纳米结构与液体接触形成的气-液-固三相界面处会形成微小空隙层，提供更多空气，对表界面处发生的化学催化反应尤其是涉及氧化反应的过程产生一定促进作用。因此，本项目制备了若干种类具有三维微纳米结构的基底材料，对其结构和形貌进行了调控，进行表面能修饰之后，形成了气-液-固三相界面，利用SERS技术在气-液-固三相界面处对表面等离激元催化反应进行快速、原位监测，建立新方法进一步对芳香胺和硝基化合物的异常SERS增强效果进行解释验证与研究。以气-液-固三相界面的特殊状态为基础，以超疏水贵金属微纳米多级结构为研究对象，发挥仿生超疏水SERS基底在表面等离激元催化反应原位检测中的优势，促进了表面增强拉曼光谱相关领域的科学研究和技术实践。