Banbury Carl, Rickard Jonathan James Stanley, Mahajan Sumeet, Goldberg Oppenheimer Pola
School of Chemical Engineering, College of Engineering and Physical Sciences , University of Birmingham , Birmingham B15 2TT , U.K.
Department of Physics, Cavendish Laboratory , University of Cambridge , JJ Thomson Avenue , Cambridge CB3 0HE , U.K.
ACS Appl Mater Interfaces. 2019 Apr 17;11(15):14437-14444. doi: 10.1021/acsami.9b00420. Epub 2019 Apr 5.
Surface-enhanced Raman spectroscopy (SERS) pushes past the boundaries and inherent weaknesses of Raman spectroscopy, with a great potential for a broad range of applications particularly, for sensing. Yet, current real world applications are limited due to poor reproducibility, low-throughput, and stability issues. Here, we present the design and fabrication of self-assembly guided structures based on adjustable block co-polymer (BCP) nanomorphologies and demonstrate reproducible SERS enhancement across large areas. Golden three-dimensional (3D) nanostructured morphologies with controllable dimensions and morphologies exhibit high chemical stability, enhanced plasmonic properties and are highly suitable for SERS substrates due to the strong enhancement of the electromagnetic field. Adjustable, free standing porous nanostructures, continuous in 3D space are achieved by removal of selected BCP constituents. Four BCP morphologies and the corresponding achievable enhancement factors are investigated at 633 and 785 nm excitation wavelengths. The choice of excitation laser is shown to greatly affect the observed signal enhancement, highlighting the sensitivity of the technique to the underlying surface architecture and length scales. By using BCP assemblies, it is possible to reliably tune these parameters to match specific applications, thus bridging the gap toward the realization of applied metamaterials. The fabricated SERS platforms via three-dimensional block co-polymer-based nanoarchitectures provide a recipe for intelligent engineering and design of optimized SERS-active substrates for utilization in the Raman spectroscopy-based devices toward enabling the next-generation technologies fulfilling a multitude of criteria.
表面增强拉曼光谱（SERS）突破了拉曼光谱的界限和固有弱点，在广泛的应用领域，特别是传感领域具有巨大潜力。然而，由于可重复性差、通量低和稳定性问题，目前其在实际应用中受到限制。在此，我们展示了基于可调嵌段共聚物（BCP）纳米形态的自组装导向结构的设计与制造，并证明了在大面积上可重复的SERS增强。具有可控尺寸和形态的金色三维（3D）纳米结构形态具有高化学稳定性、增强的等离子体特性，并且由于电磁场的强烈增强，非常适合作为SERS基底。通过去除选定的BCP成分，可实现三维空间中连续的可调独立多孔纳米结构。在633和785 nm激发波长下研究了四种BCP形态以及相应可实现的增强因子。结果表明，激发激光的选择对观察到的信号增强有很大影响，突出了该技术对底层表面结构和长度尺度的敏感性。通过使用BCP组件，可以可靠地调整这些参数以匹配特定应用，从而弥合向应用超材料实现迈进的差距。通过基于三维嵌段共聚物的纳米结构制造的SERS平台为智能工程和设计优化的SERS活性基底提供了方法，以便在基于拉曼光谱的设备中使用，从而实现满足多种标准的下一代技术。
