High Speed DNA-based Motors for Chemical Sensing

本项目由美国国家科学基金化学学部化学测量与成像（CMI）项目资助。埃默里大学的哈立德·萨莱塔教授正在开发一种基于检测dna马达运动的化学传感新方法。化学传感在从护理点诊断到农业和环境可持续性等领域具有广泛的重要性。生物系统中的传感通常发生在远离平衡的条件下，然而大多数化学分析是在或接近平衡的条件下进行的。鉴于生物传感的非凡敏感性，考虑在远离平衡的条件下进行传感的方法是可取的。在追求控制良好的非平衡反应的过程中存在固有的挑战，这些反应可以用于复杂的化学测量。该资助项目解决了这些挑战，并有可能改进当前分析化学的方法。更广泛的影响包括教育和推广目标，重点是开发新的本科和研究生课程，将3D打印作为化学科学的工具。该课程是为一年级研究生和本科生量身定制的，提高了他们在自己的研究工作中利用3D打印的能力。Salaita教授的实验室研究了一种新型合成DNA马达，其运行速度比目前的DNA马达快1000倍。这些马达可以将5微米的粒子传输到1毫米的距离。由于马达运输的机制依赖于包括沃森-克里克碱基配对和RNA催化水解在内的多步反应，因此马达的速度可以作为分析物浓度的报告物。使用自动图像分析对DNA传感进行了优化。重点是通过测量粒子速度响应目标寡核苷酸的单核苷酸多态性来测试检测的特异性。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.