Advanced three-dimensional lab-on-a-chip architectures for integrated surface-enhanced Raman spectroscopy (LoC-SERS)

芯片实验室表面增强拉曼光谱（SERS）是一种非常有前途的水中低浓度分析物的灵敏生化检测方法。然而，有两个问题需要解决。首先，低成本制造具有高可重复性的片上集成SERS纳米结构仍然是一个空白。其次，芯片上集成的激光激发源，特别是光谱可调的激光源，仍然缺乏这种应用。这一建议提出了一种跨学科的方法，将微/纳米系统工程和纳米光子学相结合，用于表面增强拉曼光谱的应用。该项目的主要目标是集成有机半导体激光器的片上拉曼光流平台的技术实现。此外，我们的目标是基本理解和优化局部表面等离子体共振（LSPR）的SERS应用，使用低成本的金属-有机混合纳米结构阵列。我们的工作将主要解决以下几个问题：利用激光辅助热压印，将周期性纳米图案定义为聚合物衬底的过程进行了探索。本文将在非集成SERS衬底上实验表征金属-有机杂化纳米图案的拉曼增强因子。2)。利用时域有限差分（FDTD）建模仿真研究不同几何形状的周期性纳米图案，旨在提高不同激发波长下的SERS增强因子，用于生化分析。将与实验工作保持密切的反馈回路。3)。优化后的纳米图案将被集成到聚合物芯片上的微流控通道中。作为集成的进一步步骤，将使用激光辅助复制和喷墨打印的组合将有机半导体分布式反馈（DFB）激光器引入芯片。SERS芯片用聚合物盖封装后定型，通过激光透射焊接实现。4)。使用有机DFB激光器的SERS激发将以第一种方式通过引入外部光学元件，例如商用离轴抛物面镜来实现。第二种方法是利用包含集成光学元件的功能性聚合物盖实现对sers分析场的垂直激光激发。利用系统光学设计对集成反射镜的几何形状和公差进行了研究。封装过程将通过激光传输焊接实现，定位精度高。5)。最后，我们将基于我们制造的sers纳米模式和LOC-SERS芯片进行首次生化测试。因此，我们的目标是展示现场在线水质监测和生物医学诊断的癌症特异性突变的致癌基因的肽。

Lab-on-a-chip surface-enhanced Raman spectroscopy (SERS) is a very promising method for sensitive biochemical detection of low-concentrated analyte in water. However, two issues should be addressed. First, low-cost fabrication of on-chip-integrated SERS nanostructures with high reproducibility in enhancement factor is still vacant. Second, an on-chip-integrated laser excitation source, especially a spectrally tunable laser source, is still missing for this application. This proposal suggests an interdisciplinary approach, combining micro-/nano-systems engineering and nanophotonics for surface-enhanced Raman spectroscopy applications. The main objective of the project is the technical realization of a Raman-on-chip optofluidic platform with integrated organic semiconductor lasers. Furthermore we aim at a fundamental understanding and an optimization of localized surface plasmon resonances (LSPR) for SERS applications using low-cost metal-organic hybrid nanostructure arrays. Our work will mainly address the following issues: 1.) Using laser-assisted hot embossing, the process for defining periodic nanopatterns into polymeric substrate will be explored. The Raman enhancement factor of metal-organic hybrid nano-patterns will be experimentally characterized on non-integrated SERS substrates. 2.) Periodic nanopatterns in various geometries will be investigated using finite-difference-time-domain (FDTD) modeling simulations, aiming to improve the SERS enhancement factor at different excitation wavelengths for biochemical analysis. A close feedback loop with the experimental work will be maintained. 3.) The optimized nanopatterns will be integrated into the microfluidic channels on a polymeric chip. As a further step of integration, organic semiconductor distributed feedback (DFB) lasers will be introduced onto the chip using a combination of laser-assisted replication and ink-jet printing. The SERS chip will be finalized after the encapsulation with a polymeric lid, which will be achieved by laser transmission welding. 4.) SERS excitation using an organic DFB laser will be realized in the first way by introducing external optical elements, e.g., commercial available off-axis parabolic mirrors. In the second way, a functional polymeric lid which comprises integrated optical components is to achieve a perpendicular laser excitation on SERS-analysis fields. The geometry and tolerance of integrated mirrors will be investigated using systematic optics design. The encapsulation process will be achieved by laser transmission welding with high precision in positioning. 5.) Finally we will perform first biochemical tests based our fabricated SERS-nanopatterns and LOC-SERS chips. Therefore we aim at demonstrating on-site inline water quality monitoring and moreover biomedical diagnostics of cancer-specific mutations in the oncogene of the peptide.