CAREER: Tunable Graphene Microelectrodes for Real-time Biological Sensing

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).

With the support of the Chemical Measurement and Imaging (CMI) Program in the Division of Chemistry, Ashley Ross of the University of Cincinnati is studying how graphene, a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice, can be used to sense neurochemicals. By controlling the direction of the carbon atoms in the honeycomb and placing different kinds of atoms on the surface of the graphene, Dr.

Ross and their research team will work toward making electrodes that can electrically communicate in an effective way with chemicals that are key to understanding the nervous system. This new approach with graphene electrodes offers the possibility of systematically studying how tuning the orientation of the honeycomb edge and the surface chemistry of graphene can be used to make electrodes capable of sensing neurochemicals better than methods known for 40-years.

Such tunable electrodes are expected to offer extremely rapid sensing of changes in the amounts of neurochemicals within very tiny areas of the body, which would be very valuable to understanding the way messages are sent and received by the nervous system. This new route to making tailored and rapid sensing of neurochemicals may shed light on the way in which a variety of cells are given and receive instructions to initiate, stop, or regulate biological responses.

Importantly, the new graphene fiber electrodes have the potential to give a glimpse into the immune response and its programming by neurochemicals, by detecting fast changes in their amounts in whole organs. The project is anticipated to have a long-term impact on sensing by providing new measurement tools and an understanding of how the surface of the electrode and the structure of neurochemicals influence their detection.

The impact of the project is to be broadened by building on an on-line discussion platform and seminar series, titled “Analytical Chemistry Diversity Colloquium”, to increase engagement and to nationally promote the work of underrepresented scientists in analytical chemistry. In addition, this project will develop multidisciplinary and discussion-based modules to be incorporated into courses to improve scientific literacy, create an environment of inclusion, and excite students from diverse backgrounds about analytical chemistry.

There is a current knowledge gap in electrochemical sensing about enabling correlation and prediction of how changes in electrode structure and chemistry impacts the interface between solution-phase analytes having different structures and the electrode surface. The ability to precisely control and correlate how specific chemical and structural properties of the electrode impact detection of electroactive biomolecules will significantly influence our understanding of electrode-analyte interactions to enable exquisitely designed electrode surfaces for improved real-time biological sensing.

In this project, we will advance knowledge of analyte-electrode interactions with fast-scan cyclic voltammetry because it is the primary electrochemical method used to probe real-time neurochemical signaling; therefore, this approach will have a major impact on dynamic neurochemical sensing. This project will focus on synthesizing and characterizing tunable graphene fiber microelectrodes to measure how carbon surface orientation and alignment, functionalization, surface energy, and three-dimensional structure impact electrochemical detection of neurochemicals.

This proposal will ultimately enable expansion of real-time neurochemical sensing to beyond the brain to study nervous system regulation of immunity, communication along the gut-brain axis, and more, by providing significantly improved electrodes that enable ultra-sensitive and high-temporal-resolution measurements.

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.