# Implantable Microarray Probe for Real-Time Glutamate and GABA Detection

> **NIH NIH R42** · ALCORIX · 2023 · $903,957

## Abstract

Project Summary
This STTR proposal will focus on developing and testing a novel, first-on-the-market implantable biosensor for
in vivo, real-time sensing of gamma-aminobutyric acid (GABA) and glutamate (GLU) for animal studies. GABA
and GLU are neurotransmitters (NTs) that are essential for information processing and plasticity, memory, and
other functions. GLU is the major excitatory NT and GABA is the major inhibitory NT; a proper balance between
them is vital for normal brain function. GLU-GABA dysregulation plays a critical role in several brain disorders,
including epilepsy (a disease affecting 1.2% of Americans), dementia (which will affect 130M worldwide by 2050)
and Parkinson’s (which affects 1.5M Americans today). A fundamental understanding of NT homeostasis
including its temporal components and its role on behavioral events within and across brain areas would lead to
a better understanding of human brain function and to new and more effective treatments. Existing NT sensing
methods measure only one NT at a time, suffer from poor spatiotemporal resolution, are unable to measure NT
dynamics at the circuit level, continuously in real time. Our goal is to develop an ultra-small, flexible (50µm)
neural probe for chronic, direct and simultaneous amperometric detection of GLU&GABA, with sub-second
temporal resolution and with no externally applied reagents. Phase I focused on manufacturing a prototype Si
penetrating shank-type probe with 4 micropatterned sensors and one microfluidic on-demand in-situ calibrator
(ODIC), optimizing the enzyme functionalization process, and performing a feasibility study on the measurement
of physiologically-relevant changes in the levels of GLU&GABA in real time for freely moving rats for up to 2
weeks. The objectives of Phase II are an upgrade of the probe into a brain micromotion-resistant hybrid Si-
flexible polymer probe of higher functionality (octrode + 2 ODIC micro-channels), improvements in selective
functionalization, and validation of the probes in a rat model of temporal lobe epilepsy. The multifunctional ODICs
will be applied to perform in-situ calibrations for chronic measurements and to investigate the circuit activity of 3
adjacent cortical layers in the whisker barrel cortex via chemical modulation. Upon completion, we expect to
deliver a unique-on-the-market dual NT probe of excellent reliability and superior sensitivity, selectivity, and
stability, with all performance parameters equal to or better than those offered by current technologies. To
achieve this, Alcorix will partner with experts in amperometric NT sensing research from Louisiana Tech U. and
experts in the manufacture of advanced neuroprobes from NeuroNexus, who will assist with hybrid Si-flexible
polymer integration, in vitro and in vivo evaluation, and eventual market entry. The proposed research will also
enable alternative uses such as point-of-use sensors for neurotoxins or disease bio-markers, and neural signal
recording or ...

## Key facts

- **NIH application ID:** 10761486
- **Project number:** 2R42NS115282-02A1
- **Recipient organization:** ALCORIX
- **Principal Investigator:** Prabhu Arumugam
- **Activity code:** R42 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $903,957
- **Award type:** 2
- **Project period:** 2023-09-18 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10761486

## Citation

> US National Institutes of Health, RePORTER application 10761486, Implantable Microarray Probe for Real-Time Glutamate and GABA Detection (2R42NS115282-02A1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10761486. Licensed CC0.

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