Nanopore Arrays with Tunable Chemistry for Mimicking Feedback Loops

University Of California-Irvine, Irvine CA

Investigators

Abstract

With support from the Chemical Measurement and Imaging (CMI) program in the Division of Chemistry, Professor Zuzanna Siwy of the University of California, Irvine will fabricate nanopore arrays that mimic feedback loops. Nanopores are holes with a diameter that is thousands of times smaller than the thickness of a human hair and are the basis of a multitude of physiological processes in living systems, including nerve signaling, vision and hearing among others. Biological nanopores are embedded in the cell membrane and often function together as a complex circuit. Inspired by biology, the Siwy group intends to fabricate nanopore arrays where the position and geometry of individual nanopores will be controlled. The arrays will function in aqueous solutions of salts in conditions that mimic functioning of a biological cell. Nanopores in these arrays interact with each other, such that transport of ions and water through individual nanopores will depend on the presence, number as well as chemical properties of neighboring nanopores. The arrays will allow preparation of very sensitive biological sensors and circuits with interesting transport properties, which will enable spreading of a signal, such as a binding of a molecule, over the whole array. This research project will provide multidisciplinary training for a diverse group of graduate students and help to prepare the future STEM (science, technology, engineering and mathematics) workforce. Under this award, the Siwy group will prepare nanopore arrays with 3, 6, and up 16 nanopores using an electron beam in a transmission electron microscope. The focus of the research program will be to provide design principles for tunable nanopore arrays where interactions between nanopores can be controlled through position and number of nanopores as well as tuning electrochemical properties of the pore walls. The nanopore arrays will be integrated with a nanoscopic gold electrode placed in the proximity of the nanopores. The electrode will provide a localized electrical or chemical signal that will be amplified and propagated by the array in space and time. Examples of positive and negative feedback loops will be prepared where the local signal such as a product of an enzyme at the electrode will cause either gradual opening or closing of all nanopores in the array, respectively. Such nanopore arrays have the potential to will mimic biological feedback loops important in processes such as wound healing and maintaining blood pressure and, as such, both advance the technology for next generation sensors, but also shed light on the mechanisms of molecular level feedback in Nature. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.