The idea of molecular electronics is usually stated in terms of miniaturization, scaling, and the difficulties of extending silicon technologies. Aside from digital logic, however, molecule-based architectures could also be novel transducers of chemical activity. For example, single molecule electronic devices might be used to merge solid state electronics with the dynamic behavior of constituent biomolecules. This novel repurposing might be the most transformative and impactful outcome of fabricating devices at molecular scales, since no electronic product today incorporates proteins, DNA, or any other biomolecule in a functional way. Even if molecular devices never compete with traditional digital electronics as memory or transistor devices, these alternate purposes represent untapped new fields with tremendous potential import.
For example, imagine a silicon chip device that could report the function of a particular enzyme, or medicine, or catalyst particle. Directly reporting chemical activity with a solid state device could give users new insights into chemistry happening in real time. This new information would enable the efficient development of new drugs, or the in situ testing of catalysts to check their effectiveness.
This project aims to experimentally demonstrate and test this premise, and furthermore to monitor chemical activity with molecule-by-molecule precision. The work is made possible by a recently developed architecture in which single molecules are integrated into functioning carbon nanotube transistor devices. The nanotube conductance records chemical events in real time with microsecond resolution, as the attached molecule interacts with its immediate environment. Past work has successfully recorded complex, time varying signals associated single molecule chemistry. However, the generality of the devices remains unproven, and there is no understanding of how chemical, electronic, and mechanical degrees of freedom combine to generate the signals of interest. A primary goal of this project will be to develop an understanding these possible contributions, in order to develop design rules for how to refine and control the mechanisms at work.
Intellectual Merit: This proposal makes effective use of recent discoveries to push forward the field of molecular electronics, and it does so in a direction of immediate practicality. The goals are designed to improve our fundamental understanding of signal transduction in single molecule devices, a critical step before such devices can be commercialized for practical applications. The project is timely and well-positioned because it leverages other ongoing research efforts, it is immediately technically feasible, and suggestive preliminary data exist.
Broader Impacts: If successful, this project may help develop an electronic device having wide-ranging commercial significance. As a high sensitivity and high bandwidth sensor it could benefit a wide spectrum of the medical and pharmaceutical industries through new diagnostic and research capabilities, independent of fluorophores or other optical equipment. There are also potential benefits to chemical processing generally, through improved process monitoring and control. The project will also directly support the research training of junior scientists, and the training of science majors interested in becoming K-12 science teachers.
