Electronic DNA detection on semiconductors involving DNA nanospheres

本研究的目的是开发新的方法，用于半导体电极上的电子DNA检测，使用DNA功能化的金纳米球，以实现信号放大。该方法基于测量这些DNA功能化金纳米球结合后表面电荷密度的变化，这会通过场效应导致半导体阻抗响应的变化。在半导体表面上的电子DNA检测的当前限制是灵敏度和响应时间。该项目旨在通过外部电场加速目标寡核苷酸和DNA纳米球的表面固定来改善响应时间。它旨在通过利用DNA纳米球的大电荷体积比，通过探索基于电荷隧穿到金属纳米球的额外信号放大的机制，以及通过将电子检测与新型等温DNA扩增反应（EXPAR）耦合来提高灵敏度。增加的灵敏度将使设备小型化，这将在传感器microarray的制造中加以利用，该项目的结果预计将有助于以小型化，便携式格式进行临床诊断和生物威胁应用的快速DNA检测。这个跨学科的研究项目汇集了来自三个不同机构的化学，生物学和工程专业知识的合作者团队。它将提供机会，联合收割机的研究资源，并将使本科生在所有三个机构进行研究，合并电子与纳米科学和生物技术。该项目将加强涉及克莱蒙联合学区的外联活动，特别是克莱蒙高中的AP科学班。

The objective of this research is to develop new methods for electronic DNA detection on semiconductor electrodes, using DNA-functionalized gold nanospheres to achieve signal amplification. The approach is based on measuring changes in surface charge density upon binding of these DNA-functionalized gold nanospheres, which lead to a shift in the semiconductor's impedance response through the field effect. Current limitations of electronic DNA detection on semiconductor surfaces are sensitivity and response time. This project aims to improve response time by accelerating the surface immobilization of target oligonucleotides and DNA nanospheres through an external electric field. It seeks to improve sensitivity by taking advantage of the large charge to volume ratio of DNA nanospheres, by exploring a mechanism for additional signal amplification based on charge tunneling to the metal nanospheres, and by coupling electronic detection with a novel isothermal DNA amplification reaction (EXPAR). Increased sensitivity will enable device miniaturization, which will be harnessed in the fabrication of a sensor microarray.The results of this project are expected to facilitate rapid DNA detection for clinical diagnostics and bio-threat applications in a miniaturized, portable format. This interdisciplinary research project brings together a team of collaborators with expertise in chemistry, biology, and engineering from three different institutions. It will provide the opportunity to combine research resources, and will enable undergraduate students at all three institutions to conduct research that merges electronics with nanoscience and biotechnology. The project will strengthen outreach involving the Claremont Unified School District, specifically the AP science classes of Claremont High School.