Characterisation of a microelectrochemical biosensor for real-time detection of brain extracellular d-serine.

Autor: Doran MM; Neurochemistry Laboratory, Maynooth University Department of Chemistry, Maynooth University, Maynooth, Co. Kildare, Ireland. Electronic address: Michelle.Doran@mu.ie., Bermingham KP; Neurochemistry Laboratory, Maynooth University Department of Chemistry, Maynooth University, Maynooth, Co. Kildare, Ireland., Tricklebank MD; Department of Neuroimaging Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK., Lowry JP; Neurochemistry Laboratory, Maynooth University Department of Chemistry, Maynooth University, Maynooth, Co. Kildare, Ireland. Electronic address: John.Lowry@mu.ie.
Jazyk: angličtina
Zdroj: Talanta [Talanta] 2024 Oct 01; Vol. 278, pp. 126458. Date of Electronic Publication: 2024 Jun 22.
DOI: 10.1016/j.talanta.2024.126458
Abstrakt: A modified development protocol and concomitant characterisation of a first generation biosensor for the detection of brain extracellular d-serine is reported. Functional parameters important for neurochemical monitoring, including sensor sensitivity, O 2 interference, selectivity, shelf-life and biocompatibility were examined. Construction and development involved the enzyme d-amino acid oxidase (DAAO), utilising a dip-coating immobilisation method employing a new extended drying approach. The resultant Pt-based polymer enzyme composite sensor achieved high sensitivity to d-serine (0.76 ± 0.04 nA mm -2 . μM -1 ) and a low μM limit of detection (0.33 ± 0.02 μM). The in-vitro response time was within the solution stirring time, suggesting potential sub-second in-vivo response characteristics. Oxygen interference studies demonstrated a 1 % reduction in current at 50 μM O 2 when compared to atmospheric O 2 levels (200 μM), indicating that the sensor can be used for reliable neurochemical monitoring of d-serine, free from changes in current associated with physiological O 2 fluctuations. Potential interference signals generated by the principal electroactive analytes present in the brain were minimised by using a permselective layer of poly(o-phenylenediamine), and although several d-amino acids are possible substrates for DAAO, their physiologically relevant signals were small relative to that for d-serine. Additionally, changing both temperature and pH over possible in vivo ranges (34-40 °C and 7.2-7.6 respectively) resulted in no significant effect on performance. Finally, the biosensor was implanted in the striatum of freely moving rats and used to monitor physiological changes in d-serine over a two-week period.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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