Biofunctional Nanofibers for Analyte Separation in Microfluidic Channels

0852900 Baeumner生物功能纳米纤维用于微流控芯片中的分析物分离生物分析微系统是小型化的生物化学和分子生物学测定，其依赖于生物分子（如抗体、受体和核酸）与感兴趣的分析物的高度特异性结合。利用其小的特征尺寸，小型化分析系统提供小的样品体积、高度并行的过程，从而提供良好的多分析物检测能力。它是一个成熟的研究领域，在文献中描述了许多基于各种检测和识别原理的系统。剩下的关键挑战是样品制备和样品浓缩步骤的整合。在化合物的复杂混合物中识别分析物的能力对于任何检测系统都是具有挑战性的，并且需要部分依赖于生物识别分子特异性结合和/或与其分析物反应的能力。然而，微通道的污染和需要自动分离的分析物出其矩阵，使其更加复杂的微系统。静电纺丝是一种纤维形成工艺，其依赖于电力而不是机械力来形成纳米和微米级（100 nm至10微米）纤维。纤维可以直接静电纺丝到导电表面，如铜和金。建议调查的可能性，将电纺纳米纤维的样品纯化和分析物浓度内的聚甲基丙烯酸甲酯微流体通道。首先，纳米纤维将在通道内、穿过通道并沿着通道长度纺丝，从而在聚合物微通道内提供具有高表面与体积比的3D结构。将研究纳米纤维与通道表面的溶剂键合，并测量它们的附着强度。将纺制含有碳纳米管的导电纳米纤维，并研究其安培和电化学发光反应。第二，在纺丝过程之前，使用链霉亲和素和DNA探针作为模型，将生物识别元件包括在纳米纤维中（导电和非导电）。这些功能性生物纳米纤维将使用各种光谱学和显微镜技术以及拉伸测试技术进行物理表征，以确认生物分子的成功掺入，这种掺入对纤维形态和机械性能的影响，并确定生物分子在纤维内的位置。纳米纤维的特征在于它们的生物识别能力，使用脂质体杂交和结合试验，以前在我们的实验室开发。第三，这些结合在微通道中的功能纤维将被研究为生物分离器;作为电极; 3D引导线和集中器，并将与具有负和正表面电荷的纳米纤维结合，具有疏水性，亲水性表面。该提案的科学价值在于研究纳米纤维与基于聚合物的微流体通道的整合及其作为生物功能纳米纤维的用途。短期目标包括研究静电纺丝条件对链霉亲和素和DNA探针稳定性的影响，它们在纳米纤维表面的有效呈现以及作为生物分离器和浓缩器的有用性。长期目标是将该技术扩展到其他蛋白质和核酸分子，将导致对嵌入情况下生物识别分子活动的理解。据推测，蛋白质分子包封在纤维中时比在溶液中或表面固定时更稳定。最后，可以根据这些初步发现设计复杂的3D生物分离器和浓缩器。拟议研究的更广泛影响将是其直接适用于临床，食品，环境和生物安全应用的现场和实验室诊断测试。参与该研究的两名研究生和至少四名本科生将获得纤维科学、生物学和纳米技术工程方面的跨学科培训。康奈尔大学新视野项目的高中生将在整个学年参与研究，奥农达加部落高中的高年级学生将被招募参加暑期实习。一名高中教师和其他本科生将通过康奈尔材料研究中心的项目纳入该项目。

0852900BaeumnerBiofunctional Nanofibers for Analyte Separation in Microfluidic ChannelsBioanalytical microsystems are miniaturized biochemical and molecular biological assays that rely on highly specific binding of biological molecules such as antibodies, receptors and nucleic acids to an analyte of interest. Taking advantage of their small feature sizes, miniaturized analytical systems provide for small sample volume, highly parallel processes and thus good multi-analyte detection capabilities. It is a well-established research field with many systems described in literature based on various detection and recognition principles. Remaining key challenges are the integration with sample preparation and sample concentration steps. The ability to identify an analyte in a complex mixture of compounds is challenging for any detection system and needs to rely in part on the biorecognition molecule's ability to specifically bind and or react with its analyte. However, fouling of microchannels and the need for automated separation of the analyte out of its matrix renders it even more complicated for microsystems. Electrospinning is a fiber formation process that relies on electrical rather than mechanical forces to form nano and microscale (100 nm to 10 microns) fibers. The fibers can be electrospun directly onto a conductive surface such as copper and gold. It is proposed to investigate the possibility to incorporate electrospun nanofibers for sample purification and analyte concentration within polymethyl methacrylate microfluidic channels. First, nanofibers will be spun within the channel, across the channel and along the channel length providing 3D structures with high surface to volume ratios within a polymer microchannel. Solvent bonding of the nanofibers to the channel surfaces will be studied and the strength of their attachment will be measured. Conductive nanofibers containing carbon nanotubes will be spun and investigated for amperometric and electrochemiluminescence reactions. Second, biorecognition elements will be included into the nanofibers (conductive and non-conductive) prior to the spinning process using streptavidin and DNA probes as models. These functional bionanofibers will be characterized physically using a variety of spectroscopy and microscopy techniques as well as tensile testing techniques to confirm successful incorporation of biological molecules, effect of this incorporation on fiber morphology and mechanical properties and to determine the location of the biological molecules within the fibers. The nanofibers will be characterized with respect to their biological recognition ability using liposome hybridization and binding assays developed previously in our labs. Third, these functional fibers bonded in microchannels will be studied as bioseparators; as electrodes; 3D guiding lines and concentrators and will be combined with nanofibers with negative and positive surface charges, with hydrophobic, hydrophilic surfaces. The scientific merit of the proposal lies in the study of the integration of nanofibers with polymer-based microfluidic channels and their use as biofunctional nanofibers. Short term goals include the study of electrospinning conditions on the stability of streptavidin and DNA probes, their effective presentation on the surface of the nanofibers and usefulness as bioseparators and concentrators. Long term goals will broaden the technology to other protein and nucleic acid molecules, will result in an understanding of biorecognition molecule activities in embedded situations. It is postulated that protein molecules would be more stable when encapsulated in fibers than when in solution or surface-immobilized. Finally, complex 3D bioseparators and concentrators can be designed based on these initial findings. The broader impact of the proposed research will be its direct applicability to on-site and lab-based diagnostic tests for clinical, food, environmental and biosecurity applications. Two graduate and at least four undergraduate students involved in the research will obtain cross-disciplinary training in fiber science, biology and nanotechnology engineering. High school students from the Cornell New Visions program will participate in research throughout the academic year, seniors from Onondaga Tribe high schools will be recruited for summer internships. A high school teacher and additional undergraduate students will be incorporated into the program via Cornell Center for Materials Research programs.