SBIR-STTR Award

Over the last 20 years, many neuroregulators have been identified and significant progress has been made in identifying the molecular basis of neurotransmission. The in vivo dynamics of several neurochemical events have been monitored using amperometric microelectrodes, but this approach is hindered by the relatively poor selectivity of these electrodes. In this project, electrodes with excellent selectivities will be developed by incorporating a thin layer of immobilized enzyme and other protective coatings into the microelectrode. Such electrodes would allow the in vivo determination of nonelectroactive species for the first time. Initially, an electrode for the determination of the potent neuroexcitatory amino acid, glutamate, was developed, because it has been identified in many neuronal pathways and is normally present in fairly high concentrations. The spatial, temporal, and analytical characteristics of the electrodes will be improved, and microelectrodes for other compounds important in neuroregulation will be developed in Phase II.Awardee's statement of the potential commercial applications of the research:The proposed glutamate electrode and other enzyme-based microelectrodes would be unique products, useful to trained physiologists, neuroscientists, and others active in the biosciences.National Institute of Neurological Disorders and Stroke (NINDS)

The long-term objective of this work is to develop enzyme microbiosensor-based instruments for rapid (<1 min) in vivo, intracellular detection of non-easily oxidized neurotransmitters. Specifically, in Phase II amperometric microbiosensors (< 5micro m O.D.) will be fabricated for detection of neurotransmitters glutamate, aspartate, gamma-aminobutyric acid (GABA), choline, acetylcholine, glycine and the amino acids glutamine, histidine, alanine, asparagine, valine, isoleucine, leucine, arginine, methionine, tryptophan and phenylalanine, which are possible neurotransmitters. These sensors will be used to study the rapid changes in analyte concentration that occur within neurons and in the extracellular fluid. Thus, for the first time, it will be possible to study the dynamics of processes such as neurotransmitter release and uptake within single neurons. The biosensor response in resting cells will be compared to that obtained by single cell LCEC analysis of the same cells. This technology will enable a vast increase in the fundamental knowledge of neuronal cellular processes, so aiding research into neurodegenerative diseases and facilitating the recovery of patients who have suffered brain damage.