Development of a mimetic system for electrochemical detection of glutamate

This paper describes the development of a biosensor to detect neurodegenerative diseases, focusing on Alzheimer’s disease, the most common type of dementia, based on the use of a small protein-like chain designed to mimic a peptide that recognizes glutamate, the main excitatory neurotransmitter present in the central nervous system of mammals. This system is based on the immobilization of the mimetic peptide for glutamate onto graphite electrodes. The produced bioelectrode showed interesting characteristics, such as short response time (about 10 s) and linear response range between 1 and 10 mmol L−1 for glutamate, indicating a promising approach for the diagnosis of neurological diseases. In addition, it was possible to observe differences in charge transfer resistance and in surface topography of the electrode, after the interaction with the glutamate target. Theoretical calculations suggest that the anchoring of glutamate indicates conformational changes in the peptide. The mimetic bioelectrode discriminates samples from patients with Alzheimer’s disease.