High Speed DNA-based Motors for Chemical Sensing

该项目由美国国家科学基金会化学部的化学测量和成像（CMI）计划资助。埃默里大学的Khalid Salaita教授正在开发一种新的化学传感方法，该方法基于检测基于DNA的马达的运动。化学传感对于从护理点诊断到农业和环境可持续性的领域都非常重要。生物系统中的感测通常发生在远离平衡的条件下，然而大多数化学测定在平衡条件下或接近平衡条件下进行。考虑到生物传感的非凡灵敏度，期望考虑在远离平衡的条件下进行传感的方法。在追求良好控制的反应方面存在固有的挑战，这些反应在不平衡的情况下进行，并且可以用于复杂的化学测量。该资助项目解决了这些挑战，并可能改善分析化学的现有方法。更广泛的影响包括教育和推广目标，重点是开发新的本科生和研究生课程，将3D打印作为化学科学的工具。该课程专为一年级的研究生和本科生量身定制，旨在提高他们在自己的研究工作中利用3D打印的能力。Salaita教授的实验室已经研究了一类新的基于合成DNA的马达，其运动速度比目前基于DNA的机器快1000倍。这些马达将5微米的颗粒输送到1毫米的距离。由于马达转运的机制取决于涉及沃森-克里克碱基配对和RNA催化水解的多步反应，因此马达的速度可以用作分析物浓度的报告者。使用自动化图像分析优化该测定用于DNA传感。重点是通过测量响应于靶寡核苷酸的单核苷酸多态性的颗粒速度来测试测定的特异性。这项工作研究了功能性寡核苷酸，从而扩大了基于运动的传感范围，以检测重金属和小分子分析物。

This project is funded by the Chemical Measurement and Imaging (CMI) Program of the Division of Chemistry at the National Science Foundation. Professor Khalid Salaita of Emory University is developing a new approach for chemical sensing that is based on detecting the motion of DNA-based motors. Chemical sensing is broadly important for fields ranging from point of care diagnostics to agriculture and environmental sustainability. Sensing in biological systems typically occurs in conditions that are far-from-equilibrium, yet most chemical assays are performed at or near equilibrium conditions. Given the extraordinary sensitivity of biological sensing, it is desirable to consider approaches to sensing under conditions that are far-from-equilibrium. There are inherent challenges in pursuing well-controlled reactions that operate out of equilibrium and that can be harnessed for sophisticated chemical measurements. The funded project addresses these challenges and potentially improves current approaches in analytical chemistry. The broader impacts include educational and outreach goals focused on developing new undergraduate and graduate courses that use 3D printing as a tool for the chemical sciences. The course is tailored toward first-year graduate students and undergraduates and enhances their ability to leverage 3D printing in their own research efforts.Professor Salaita's laboratory has examined a new class of synthetic DNA-based motors that move at a speed that is 1000 times faster than current DNA based machines. These motors transport 5-micron particles distances of up to one millimeter. Because the mechanism of motor transport depends on a multistep reaction that involves Watson-Crick base-pairing and catalytic hydrolysis of RNA, the speed of the motor can be used as a reporter of analyte concentration. This assay is optimized for DNA sensing using automated image analysis. The focus is on testing the specificity of the assay by measuring particle speed in response to single nucleotide polymorphism of the target oligonucleotide. The work investigates functional oligonucleotides, thus expanding the scope of motion-based sensing to detect heavy metals and small molecule analytes.