Centro de Ciências Químicas, Farmacêuticas e de Alimentos, Universidade Federal de Pelotas, Rio Grande do Sul, 96010-900, P.O. Box 354, Pelotas, RS, Brazil.
Phys Chem Chem Phys. 2012 Feb 14;14(6):2050-5. doi: 10.1039/c2cp23287a. Epub 2012 Jan 10.
This manuscript reports on the fabrication of plasmonic substrates using cathodic arc plasma ion implantation, in addition to their performance as SERS substrates. The technique allows for the incorporation of a wide layer of metallic nanoparticles into a polymer matrix, such as PMMA. The ability to pattern different structures using the PMMA matrix is one of the main advantages of the fabrication method. This opens up new possibilities for obtaining tailored substrates with enhanced performance for SERS and other surface-enhanced spectroscopies, as well as for exploring the basic physics of patterned metal nanostructures. The architecture of the SERS-active substrate was varied using three adsorption strategies for incorporating a laser dye (rhodamine): alongside the nanoparticles into the polymer matrix, during the polymer cure and within nanoholes lithographed on the polymer. As a proof-of-concept, we obtained the SERS spectra of rhodamine for the three types of substrates. The hypothesis of incorporation of rhodamine molecules into the polymer matrix during the cathodic arc plasma ion implantation was supported by FDTD (Finite-Difference Time-Domain) simulations. In the case of arrays of nanoholes, rhodamine molecules could be adsorbed directly on the gold surface, then yielding a well-resolved SERS spectrum for a small amount of analyte owing to the short-range interactions and the large longitudinal field component inside the nanoholes. The results shown here demonstrate that the approach based on ion implantation can be adapted to produce reproducible tailored substrates for SERS and other surface-enhanced spectroscopies.
这篇手稿报告了使用阴极弧等离子体离子注入制造等离子体基片的情况，以及它们作为 SERS 基片的性能。该技术允许将广泛的金属纳米粒子层掺入聚合物基质中，例如 PMMA。使用 PMMA 基质来形成不同结构的能力是制造方法的主要优点之一。这为获得具有增强的 SERS 和其他表面增强光谱性能的定制基片开辟了新的可能性，同时也为探索图案化金属纳米结构的基本物理提供了新的可能性。通过将激光染料（若丹明）掺入聚合物基质中、在聚合物固化过程中以及在聚合物上光刻的纳米孔内三种吸附策略来改变 SERS 活性基片的结构。作为概念验证，我们获得了三种基片的若丹明 SERS 光谱。在阴极弧等离子体离子注入过程中，将若丹明分子掺入聚合物基质中的假设得到了 FDTD（有限差分时间域）模拟的支持。在纳米孔阵列的情况下，若丹明分子可以直接吸附在金表面上，然后由于短程相互作用和纳米孔内的大纵向场分量，对于少量分析物可以产生分辨率良好的 SERS 光谱。这里显示的结果表明，基于离子注入的方法可以适用于制造可重复的定制 SERS 和其他表面增强光谱基片。
