BIOSENSOR ARRAYS BASED ON SINGLE WALL CARBON NANOTUBES

基于单壁碳纳米管的生物传感器阵列

• 批准号: 7140772
• 负责人: James F. Rusling
• 金额: $ 32.46万
• 依托单位: UNIVERSITY OF CONNECTICUT STORRS
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-03 至 2011-05-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7140772
• 关键词: bacteria; bioengineering /biomedical engineering; biosensor device; carbon; chemical binding; electrical conductance; immunoconjugates; method development; microarray technology; nanotechnology; polymers; proteins; surface property; toxin

DESCRIPTION (provided by applicant): Sensitive detection of proteins and bacteria is of central importance in biomedical research, with applications to elucidating disease pathways, immunology, medical diagnostics, systems biology, functional proteomics, and new drug development. Highly selective and sensitive binding-assay arrays are increasingly important in light of emerging areas of biomedical science and intensified world bioterrorism. Sensitive, rapid, specific, multiple detection of proteins, bacteria and toxins in biological and environmental samples is critically important for public health. The broad, long term goals of this proposal are to develop highly sensitive micro- and nano-biosensor arrays for proteins and bacteria using patterned single-walled carbon nanotubes (SWNTs) and biomolecule recognition elements. Major specific applications include simultaneous measurement of suites of protein biomarkers in serum for early cancer detection. Single walled carbon nanotubes (SWNTs) with approximately 1.4 nm diameters have the world's highest conductivity per unit mass and have excellent potential for electrical sensing of biomolecules. We have assembled approximately 30 nm long carbon nanotubes standing in 20-200 nm diameter bundles called SWNT forests with electrical links to conductive surfaces. These high surface area, patternable, conductive nanostructures provide new opportunities for highly sensitive biosensor arrays. In this project, we combine nanotube electrical transduction with specific molecular recognition of antibodies for proteins and bacteria. SWNTs as molecular wires will shuttle electrons vectorially between enzyme labels at their tips and external electrical connections. We focus here on peroxidase-linked amperometric immunoassays, in which enzyme catalyzed reduction of H2O2 provides electrical signals transmitted via SWNTs. In preliminary work, we attached antibodies to SWNT forests and achieved detection of several antigens in the ng/mL range and below. Using newly developed conjugates of nanotubes, peroxidases and secondary antibodies (Ab2) with high label-to-Ab2 ratios with the SWNT immunosensors, we recently detected prostate specific antigen (PSA) in human serum at 0.01 ng/mL (0.25 Fmol/mL), a detection limit better than the best commercial assays for PSA. Ultra-low NSB combined with conductive polymer wiring of nanotube junctions, along with multi-enzyme label strategies, promise the highest possible sensitivity. Thus, we will optimize the new Ab2 nanoconjugates, explore conductive polymer wiring strategies, and eliminate non-specific binding (NSB) of interferences via competitively adsorbed protein/surfactant additives and synthesis of novel low NSB organic surfaces on nanotube ends. Finally, we will integrate optimized fabrication/detection approaches into multi-analyte sensor arrays utilizing patterned SWNT-antibody assemblies. In addition to achieving our specific aims, this project should provide fundamental guidance for fabrication of sensitive microarray devices for a wide variety of biomedical applications.

描述（由申请人提供）：蛋白质和细菌的灵敏检测在生物医学研究中至关重要，可应用于阐明疾病途径、免疫学、医学诊断、系统生物学、功能蛋白质组学和新药开发。鉴于生物医学科学的新兴领域和世界生物恐怖主义的加剧，高选择性和灵敏度的结合测定阵列越来越重要。对生物和环境样品中的蛋白质、细菌和毒素进行灵敏、快速、特异、多重检测对公共卫生至关重要。该提案的广泛的长期目标是使用图案化的单壁碳纳米管（SWNT）和生物分子识别元件开发用于蛋白质和细菌的高灵敏度的微和纳米生物传感器阵列。主要的具体应用包括同时测量血清中用于早期癌症检测的蛋白质生物标志物组。直径约为1.4 nm的单壁碳纳米管（SWNT）具有世界上最高的单位质量电导率，并具有用于生物分子电传感的优异潜力。我们已经组装了大约30纳米长的碳纳米管，这些碳纳米管以20-200纳米直径的束站立，称为SWNT森林，具有与导电表面的电连接。这些高表面积、可图案化的导电纳米结构为高灵敏度生物传感器阵列提供了新的机会。在本计画中，我们将联合收割机奈米管电转换与抗体对蛋白质及细菌的特异性分子识别结合。单壁碳纳米管作为分子导线将在其尖端的酶标记和外部电连接之间矢量地穿梭电子。在这里，我们专注于过氧化物酶联安培免疫分析，其中酶催化还原H2 O2提供通过单壁碳纳米管传输的电信号。在初步工作中，我们将抗体连接到SWNT森林，并实现了在ng/mL范围及以下的几种抗原的检测。使用新开发的纳米管，过氧化物酶和二次抗体（Ab 2）的共轭物与SWNT免疫传感器的高标记-Ab 2的比例，我们最近检测到人血清中的前列腺特异性抗原（PSA）在0.01 ng/mL（0.25 Fmol/mL），检测限优于最好的商业测定PSA。超低NSB结合纳米管结的导电聚合物布线，沿着与多酶标记策略，承诺最高可能的灵敏度。因此，我们将优化新的Ab 2纳米缀合物，探索导电聚合物布线策略，并通过竞争性吸附蛋白质/表面活性剂添加剂和在纳米管末端合成新型低NSB有机表面来消除干扰的非特异性结合（NSB）。最后，我们将整合优化的制造/检测方法到多分析物传感器阵列，利用图案化的SWNT抗体组件。除了实现我们的具体目标，这个项目应该提供基本的指导，为各种各样的生物医学应用的敏感微阵列设备的制造。