Laser-engineered nanocomposites for sensing applications

表面增强拉曼散射（Sers）是一种非常强大的光学检测平台，用于开发适用于实时监测的灵敏定量分析方法。该技术提供了关于位于靠近等离子体纳米结构的分子的振动“指纹”的信息，因此允许对检测到的分析物的类型进行独特的分类。该方法也被证明具有单分子检测能力。基于SERS的方法已经在生物分析传感中实现了许多重要的应用，例如体内肿瘤靶向，临床相关浓度的葡萄糖传感和微生物系统分析，并且被认为是纳米生物技术和个性化医疗等领域取得进展的主要先决条件。尽管表面增强拉曼光谱比常用的基于荧光的方法有明显的优势，但它还没有被确立为一种分析工具。这在一定程度上是由于Sers基底中的小变化（制备、聚集、表面形态等）对Sers性能有显著影响。目前SERS活性基底的制备技术主要有电子束光刻法、纳米压印法、自组装纳米球法、混合纳米孔光刻法、纳米孔光刻法等，这些方法具有中到高的增强因子和可重复的均匀响应。这些技术对于大面积Sers基底的生产仍然是昂贵的并且相当麻烦，因此商业上可获得的Sers平台的价格高。该项目的重点是展示基于激光工程纳米复合材料系统的新型Sers平台，以大幅提高性能和制造控制，解决当前Sers材料的局限性。定制的Ag-/Au-离子和Ag-/Au-纳米粒子掺杂的基板具有不同的掺杂剂浓度和体积填充因子将被制造为适合于Sers分析与频繁使用的激发波长在光谱区域从400到1000 nm。一个空间选择性纳米复合退火技术将开发，以实现大面积的平面平台与可控的几何形状和可重复的增强因子，允许一个步骤的变化，在制造强大的传感平台定量Sers分析。此外，所提出的材料系统将形成未来微流体传感器件的构建模块，用于生物医学，环境和安全应用。

Surface-Enhanced Raman Scattering (SERS) is an extremely powerful optical detection platform for the development of sensitive and quantitative analytical methods suitable for real-time monitoring. This technique provides information about the vibronic 'fingerprint' of a molecule located close to plasmonic nanostructures and therefore allows for a unique classification of the type of analyte detected. This method has also been proven to have a single-molecule detection capability. SERS-based approaches have enabled a number of important applications in bioanalytical sensing, such as in vivo tumour targeting, glucose sensing at clinically relevant concentrations and microbial system analysis, and are considered a major prerequisite for progress in areas such as nanobiotechnology and personalised medicine. In spite of the apparent advantages over commonly used fluorescence-based methods, SERS is yet to be established as an analytical tool. This is, in part, due to the fact that small variations in the SERS substrate (preparation, aggregation, surface morphology, etc.) have drastic effects on the SERS performance. Therefore the stability and reproducibility issues of SERS-active substrates have to be addressed in order to facilitate its application in quantitative analysis.Current fabrication techniques of SERS substrates with moderate to high enhancement factors, and reproducible and uniform responses are dominated by e-beam lithography, nano-imprint, self-assembled nanosphere, hybrid nanoporous lithography methods, etc. These techniques are still costly and rather cumbersome for production of large area SERS substrates, hence the high price of commercially available SERS platforms. The focus of this project is to demonstrate novel SERS platforms based on laser-engineered nanocomposite systems for dramatically improved performance and fabrication control, addressing current SERS materials limitations. Tailored Ag-/Au-ion and Ag-/Au-nanoparticle doped substrates with different dopant concentrations and volume filling factors will be fabricated suitable for SERS analysis with frequently used excitation wavelengths in the spectral region from 400 to 1000 nm. A spatially selective nanocomposite annealing technique will be developed in order to realise large area planar platforms with controllable geometry and reproducible enhancement factors, allowing a step change in fabrication of robust sensing platforms for quantitative SERS analysis. Furthermore, the proposed material systems will form the building blocks of a future microfluidic sensing devices for biomedical, environmental and security applicatons.