Digital microfluidics (DMF) for SERS analysis on a chip with EWOD-/(w)OEW-actuated analyte droplets

导电液滴可以通过介质电润湿（EWOD）和光电润湿（OEW）来驱动。原则上，OEW控制光波甚至可以在液滴下面的层序列中进行波导（Fouckhardt的想法，基于波导的OEW = wOEW）。在化学芯片大小的实验室中，数字微流体（DMF，芯片实验室2.0）中的液滴操作是一个重要的应用。数字微流体技术在微型化化学领域取得突破的一个障碍是缺乏敏感的、非破坏性的检测方法，无法在DMF芯片上对离散液滴中的化学物质进行毫无疑问的识别。在这里提出的项目中，将首次在芯片上为此目的使用表面增强拉曼散射或光谱（SERS） （idea Belder），这将使可以很好地评估振动谱成为可能。通过分析物分子（在液滴内）的相互作用，例如与分散在液滴中的金属纳米粒子的相互作用，应该可以获得高信号放大。该项目旨在首次将DMF和SERS结合，并通过ewod - oew - wow同时驱动液滴。由光学引发的液滴运动为实现质朴的芯片实验室系统提供了新的机会。Belder和Fouckhardt集团的合作应该提供协同效应，这使得DMF技术在化学实验室芯片的背景下取得突破成为可能。Belder团队专注于DMF系统中的SERS检测。Fouckhardt小组致力于通过EWOD和OEW进一步开发液滴驱动，最好达到wOEW。此外，在密切合作下，将研究固体金属SERS靶的潜力，这些靶可能同时用作EWOD-(w)OEW技术的电触点或镜像层。组件的多功能性被认为是DMF实验室芯片进一步小型化的内在积极因素。原则上，对于任何SERS目标替代方案，都可以使用上述任何驱动变量，即EWOD、OEW或wOEW。工作计划中的（初步）分配归功于两组工作包的时间协调。在需要的情况下，对于液滴驱动，OEW（与wOEW相比）甚至EWOD（与wOEW和OEW相比）都可以作为退退位置。甚至DMF、SERS和EWOD驱动的组合也将是新的。

Electrically conducting fluid droplets can be actuated via electrowetting on dielectric (EWOD) and opto-electrowetting (OEW). In principle, the OEW control lightwave might even be waveguided within the layer sequence beneath the droplet (idea Fouckhardt, waveguide-based OEW = wOEW). An important application is represented by droplet manipulation in digital microfluidics (DMF, lab on a chip 2.0) in chemical chip-sized laboratories.An obstacle for a break-through of digital microfluidics in miniaturized chemistry is given by a lack of sensitive, non-destructive methods for detection, allowing for the doubtless identification of chemical substances in discrete droplets on a DMF chip. In the project proposed here surface-enhanced Raman scattering or spectroscopy (SERS) shall be employed for this purpose on a chip for the first time (idea Belder), which shall make well evaluable vibrational spectra possible. By the interaction of the analyte molecules (within the droplets) e. g. with metallic nanoparticles dispersed in the droplets high signal amplifications should be obtainable.The undertaking is aimed at the first-time combination of DMF and SERS and the concurrent droplet actuation by EWOD-OEW-wOEW. By the optical initiation of the droplet movement new opportunities for the realization of unpretentious lab on a chip systems should arise.The cooperation of the groups Belder and Fouckhardt should provide for synergies, which make a break-through of the DMF technology in the context of chemical lab-chips possible. The Belder group focuses on SERS detection within DMF systems. The Fouckhardt group concentrates on further development of droplet actuation via EWOD and OEW, preferably up to wOEW.Moreover, in close cooperation the potential of solid metallic SERS targets is to be investigated, which might simultaneously be used as electrical contacts or mirror layers for the EWOD-(w)OEW technologies. Multifunctionality of components is to be considered as inherently positive for further miniaturization of DMF lab chips.In principle, for any of the SERS target alternatives any of the mentioned actuation variants, i. e. EWOD, OEW, or wOEW, might be used. The (preliminary) allocation in the work program is owed to the temporal coordination of work packages of both groups.In case of need, for droplet actuation OEW (compared with wOEW) or even EWOD (compared with wOEW and OEW) might act as a fall-back position. Even the combination of DMF and SERS and EWOD actuation would be new.