High-resolution neural probes for ION-selective, multimodal brain mapping

The National Institute of Neurological Disorders and Stroke awarded $462,148 to The Trustees of Columbia University in the City of New York on July 8, 2026, under the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative (CFDA 93.372).

Columbia will develop and benchmark functional graphene nanoribbon (F-GNR) neural probes as ion-selective, multimodal recording tools for neuroscience. The project addresses the lack of existing tools with sufficient molecular specificity, spatiotemporal resolution, and chronic stability to map dynamic ionic signals in vivo. Deliverables include development of F-GNR-based neural probes for ion-selective, multimodal signal detection in biological models; demonstration of in vivo recording of dynamic ionic signals in behaving animals; and exploration of F-GNR probe potential in disease-relevant models. The probes will combine ion selectivity (sodium versus potassium) with multimodal detection using both electrical conductivity and optical detection in a single, scalable platform, and will be validated across device-level benchmarks including ion selectivity, signal fidelity, stability in biological environments, and compatibility with in vivo applications.

The period of performance runs through June 30, 2029. Work is performed in New York, New York. This is a Project Grant, a form of direct assistance funding for research and development activities.

Abstract

Understanding how ionic and neurochemical signals drive brain function is an unmet in neuroscience. Existing tools-such as microelectrode arrays, optical reporters, and genetically encoded indicators-lack the molecular specificity, spatiotemporal resolution, and chronic stability needed to map dynamic ionic signals in vivo. As a result, critical questions about how specific ionic fluxes regulate neural circuit activity and behavior remain unanswered. This is a tool building proposal to enable new neural probes with new functionality. Specifically, this proposal aims to develop and benchmark functional graphene nanoribbon (F-GNR) neural probes as a new class of ION-selective, multimodal recording tools for neuroscience. We have implanted these F-GNR based devices in vivo in rodents and found them to be highly sensitive to action potentials, biocompatible for weeks, and with the spatial and temporal resolution to monitor individual neurons. In this proposal we build from these results with exciting preliminary results to utilize new versions of these F-GNR devices that combine ION selectivity (i.e., NA+ VS. K+) with a multimodal detection scheme utilizing electrical conductivity detection and optical detection in a single, scalable platform. The functional neural probes from these F-GNR made from this proposal will validate their performance across device-level benchmarks critical for neuroscience: ION selectivity, signal fidelity, stability in biological environments, and compatibility with in vivo applications. We have the following three specific aims: 1. Develop and benchmark F-GNR-based neural probes for ION-selective, multimodal signal detection in biologically relevant models. 2. Demonstrate in vivo recording of dynamic ionic signals in behaving animals. 3. Explore the potential of F-GNR probes to capture ionic signatures in disease-relevant models. F-GNR probes enable simultaneous electrical and optical recording of ionic signals with spatial and temporal resolution of a single-neuron, providing an unprecedented window into the molecular dynamics of brain activity. We will evaluate the utility of F-GNR probes in models of epilepsy, neurodevelopmental disorders, and neurodegeneration-demonstrating their ability to detect pathophysiological ionic fluctuations in vivo. These studies will assess the broader applicability of F-GNR technology for understanding the ionic basis of brain dysfunction and inform future development. This project will deliver an early-stage, highly valuable neurotechnology that enables ION-selective, multimodal recording of neural activity in vivo-a transformative platform for neural interfaces not possible with current tools. This proposal directly supports the brain initiative's mission to develop innovative neurotechnologies and unlock new studies of brain function and disease.