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.
