Enzymes Adsorbed on Carbon Nanotubes

该项目的目标是增加参与生物医学和行为研究的代表性不足的少数民族的数量。在这方面，本项目将侧重于开发基于吸附在碳纳米管上的酶的新型生物传感器，然后通过将其集成到毛细管电泳微芯片中来展示这种生物传感器的能力。碳纳米管（CNT）在电化学生物传感器方面表现出优异的性能。CNT是生物相容的，在大范围的电位下是稳定的，对许多电化学反应表现出催化活性，并且提供电极面积的显著增加。尽管通过包封或交联酶已经取得了相当大的进展，但CNT-生物传感器的分析性能仍然存在一些基本缺陷，例如响应慢（>10秒）和灵敏度有限（~ μ M）。所提出的生物传感器将具有比标准生物传感器更大和更快的响应，并将酶的选择性、碳纳米管的催化活性和导电性与毛细管电泳微芯片的样品处理能力和分离手段相结合。本项目的假设是，可以合理选择实验条件，使酶在碳纳米管上的吸附最大化，同时保持酶的活性。由于用于吸附的条件对酶的构象和活性具有核心影响，因此我们将首先研究不同的酶如何与碳纳米管相互作用。通过分析不同条件下的吸附动力学，建立酶性质与吸附条件之间的合理联系。然后，我们将展示这些生物传感器耦合到毛细管电泳微芯片的优点。我们希望避免苛刻的结合条件（酶电极），最小化响应时间，最大化信号幅度，并减少与膜（用于捕获酶）相关的峰拖尾。由于所提出的传感器将与毛细管电泳微芯片集成，因此可以包括和自动化诸如样品预处理、进样和分离的操作。 我们将研究酶如何与碳纳米管相互作用。然后，我们将应用这些信息开发传感器来监测重要分子和诊断疾病。

DESCRIPTION (provided by applicant): The goal of this project is to increase the number of underrepresented minorities participating in biomedical and behavioral research. In that regard, this project will focus on the development of new biosensors based on enzymes adsorbed on carbon nanotubes, and then demonstrate the capabilities of such biosensors by integrating them in capillary electrophoresis microchips. Carbon nanotubes (CNT) display excellent qualities toward electrochemical biosensors. CNT are biocompatible, are stable over a large range of potentials, demonstrate catalytic activities toward many electrochemical reactions, and provide a significant increase in electrode area. Although considerable progress has been made by encapsulating or cross-linking enzymes, the analytical performance of CNT-biosensors still suffers from some fundamental deficiencies such as slow response (>10 sec) and limited sensitivity (~micro-M). The proposed biosensors will have larger and faster response than standard biosensors and will combine the selectivity of enzymes, the catalytic activity and conductivity of carbon nanotubes with the sample handling capabilities and separation means of capillary electrophoresis microchips. The hypothesis of this project is that experimental conditions can be rationally selected to maximize the adsorption of enzymes to carbon nanotubes, while preserving the enzymatic activity. Since the conditions used for the adsorption have a central effect on the enzymatic conformation and activity, we will first investigate how different enzymes interact with carbon nanotubes. By analyzing the adsorption kinetics under different conditions we will establish a rational link between enzyme properties and adsorption conditions. Then, we will demonstrate the advantages of coupling these biosensors to a capillary electrophoresis microchip. We expect to avoid harsh binding conditions (enzyme-electrode), minimize the response time, maximize the signal magnitude, and decrease the peak tailing associated with membranes (applied to trap the enzyme). Since the proposed sensor will be integrated with a capillary electrophoresis microchip, operations such as sample pretreatment, injection, and separation can be included and automated. We will study how enzymes interact with carbon nanotubes. Then, we will apply that information to develop sensors to monitor important molecules and diagnose diseases.