The Intellectual Merit The goal of this proposal is to develop biosensors based on nucleic acids called aptamers. Aptamer based biosensors are emerging as viable alternative to traditional sensors that employ antibodies for recognition of target molecules. Aptamer based biosensors are more chemically and thermally stable and may be reagentless - that is no additional processing steps are needed to generate a signal in response to target molecules. Our proposal seeks to addresses a distinct challenge in regenerating these biosensors in order to make the same sensor available for continuous in-line monitoring. We propose to use applied voltage to tune and control affinity of sensing electrodes in temporal and/or spatial manner to ensure that some electrodes are detecting association while others are monitoring dissociation events. This way up and down changes in the level of target molecules may be monitored.
Broader Impact The goal of our proposal will be to develop novel, aptamer-based microsystems for analysis and sorting of cells. It is our belief that such aptasensors are particularly advantageous for monitoring dynamic changes in the levels of proteins secreted by living cells and have numerous applications in biotechnology, cell/tissue engineering and infectious disease detection. In addition to biosensing, aptamer-modified surfaces may be used for affinity separation of cells from heterogeneous samples such as blood. This proposal will combine aspects of basic science with bioengineering to further enhance state of the art in cell analysis and manipulation by developing tunable aptamer-coated devices. We will actively recruit graduate, undergraduate and high school students to participate in the proposed experiments.
