NER: Signal Amplification in Biomolecular Detectors Using Activated Receptor Molecules

本研究的目的是将无标记生物分子检测器的灵敏度提高到基于标记的检测器（例如荧光）所达到的水平，这些检测器灵敏但耗时且昂贵。在不改变传感器结构或工作原理的情况下提高灵敏度的方法是非常可取的。该方法是将激活的受体分子整合到生物传感器中。单链DNA或基于rna的分子，即在与小靶标结合时发挥酶活性的适配酶，将被用作受体分子。因此，生物传感器将检测相对较大的适配酶的活性，而不是直接检测小目标分子的结合。由于活性将由小目标分子触发，因此它们将以极大放大的灵敏度间接检测。该技术的有效性将在一些模型无标签检测系统（包括商业和内部建造的纳米机械传感器）的表面上得到证明，其中直接结合会显示太小而无法检测的信号的小分子将通过适体酶活性间接检测到。所有实验工作将由普渡大学承担。适体酶的合成将在德克萨斯大学奥斯汀分校进行。该研究项目旨在对DNA、RNA、蛋白质和小分子等生物分子的高通量检测产生广泛影响，这些生物分子的灵敏检测对于每年夺去50万美国人生命的许多癌症的早期诊断至关重要。该项目的发现将是朝着开发快速，低成本和高分辨率生物分子探测器以及理解固体表面上生物分子相互作用迈出的重要一步。该项目还将通过建立一个跨学科的阶段，使工程学生和化学家能够相互交流和学习，从而对教育做出重大贡献。该项目的一部分也将与研究生水平的实验课程相关联。

The objective of this research is to increase the sensitivity of label-free biomolecular detectors to levels achieved by label-based detectors (e.g. fluorescence) that are sensitive but time-consuming and costly. A method that improves sensitivity without modification of sensor structure or operation principle is highly desirable. The approach is to incorporate activated receptor molecules into biosensors. Single-stranded DNA or RNA-based molecules, namely aptazymes that perform enzyme activity upon binding to small targets will be used as receptor molecules. Accordingly, biosensors will detect the activity of relatively large aptazymes as opposed to directly detecting the binding of small target molecules. Since the activity will be triggered by small target molecules, they will be indirectly detected with greatly amplified sensitivity. The efficacy of the technique will be demonstrated on the surfaces of a few model label-free detection systems (both commercial and nanomechanical sensors built in-house) whereby small molecules whose direct binding would reveal signals too small to detect will be indirectly detected via aptazyme activity. All experimental work will be undertaken by Purdue. The aptazyme synthesis will be performed at the University of Texas at Austin. This research project intends to make a broad impact on high-throughput detection of biomolecules such as DNA, RNA, proteins and small molecules whose sensitive detection is of top importance for early diagnosis of many cancers that take 500,000 American lives every year. The findings of this project will be a significant step towards the development of fast, low-cost and high-resolution biomolecular detectors and towards the understanding of biomolecular interactions on solid surfaces. This project will also have significant educational contributions by setting an interdisciplinary stage where engineering students and chemists can interact and learn from each other. A part of the project will also be linked to a graduate level laboratory course.