Design and Surface Engineering of Nanofiber-based Probes

纳米级生物工程的成功在很大程度上依赖于探测微量液体的新工具的开发。测试来自单个细胞的生物液体并对其进行操作，探测来自大小从几微米到几十微米的原始生物体的生物液体，探测来自分泌腺和微血管的生理液体，以及收集用于法医分析的探针，这些只是纳米针和纳米通道作为必要工具的几个例子。一般来说，具有分层孔隙结构的纤维在对同一样品进行液体收集，运输和分析的应用中很重要。用于这些探针的材料要求具有优异的吸收性、可控的保留/提取能力和足够的刚度。为了解决这些问题，我们建议开发具有核鞘形态的一维探针。我们使用纳米纤维纱线作为芯。由于强大的毛细作用，这些纱线保证了出色的吸收和保持能力。作为护套，我们建议不同的材料具有共同的特点，即所建议的护套有效地支持液体输送并提供足够的刚度。我们还建议用热响应聚合物接枝探针芯的内部。当稍微加热时，纳米孔会降低亲水性，并将液体从孔中挤出。因此，被测液体将被释放。总的来说，本项目的结果有望为设计新型纤维基探针（有机和无机）奠定基础，这些探针采用高渗透性对比（纳米和微米直径的孔隙）和润湿性刺激（从亲水性转变为疏水性）。可交付成果包括通过建模和实验分析的基本参数和基本吸收和传输机制目录，材料和探测装置的技术技巧和原型，研究成果的文件记录以及工程学生教育。让最聪明的高中生、本科生和研究生参与现代表面和纳米技术研究被认为是该项目的一项重要任务。随着项目的进展，我们计划为研究生开发新的课程，并通过许多行业合作伙伴传播结果。

Much of the success of nanoscale bioengineering relies on the development of new tools for probing minute amounts of liquids. Testing biofluids from and operation on individual cells, probing biofluids from primitive organisms ranging in size from fractions of microns to tens of microns, probing physiological fluids from secretory glands and microcapillaries, and collecting probes for forensic analyses are only a few examples of procedures in which nanoneedles and nanochannels are necessary instruments. In general, fibers with hierarchical pore structure are important in applications where liquid collection, transport, and analysis are performed on the same sample. Materials for these probes are required to have superior absorbency, controlled retention/extraction ability, and sufficient stiffness. To address these problems, we propose to develop one-dimensional probes with core-sheath morphology. We employ nanofiber yarns as cores. These yarns guarantee exceptional absorption and retention ability due to strong capillary action. As sheaths we suggest different materials with the common characteristic that the proposed sheaths effectively support liquid transport and provide sufficient stiffness. We also propose to graft the interior of the probe core with thermally responsive polymers. When slightly heated, the nanopores will decrease the level of hydrophilicity and push the liquid out of the pores. Therefore, the tested liquid will be released. In general, the results of this project are expected to set the basis for the design of novel fiber-based probes (organic and inorganic) employing high permeability contrast (nanometer and micrometer-diameter pores) and wettability stimulation (switching from hydrophilic to hydrophobic). The deliverables include a catalog of fundamental parameters and basic absorption and transport mechanisms analyzed through modeling and experiments, technological tricks and prototypes of materials and probing devices, documentation of research results, and engineering student educations. Involvement of the brightest high-school, undergraduate, and graduate students in modern surface and nanotechnology research is considered an important mission of this project. As the project progresses, we plan to develop new courses for graduate students and disseminate the results through many industrial partners.