Octadecylamine-Modified CuO NPs Enabling Highly Selective In Vivo Ascorbic Acid Potentiometric Detection with...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Electrochemistry

Background:

• Existing in vivo ascorbic acid (AA) sensors using galvanic redox potentiometry (GRP) struggle with sulfide interference.
• Accurate measurement of AA dynamics is crucial for understanding neurological events like cortical spreading depression (CSD).

Purpose of the Study:

• To develop a novel shielding strategy for highly selective in vivo ascorbic acid (AA) assay.
• To eliminate interference from sulfides (H2S) in AA measurements.
• To investigate the role of AA release during cortical spreading depression (CSD) in rats.

Main Methods:

• Fabrication of a novel electrode by confining octadecylamine (ODA)-modified CuO nanoparticles (NPs) on a carbon fiber electrode (CFE).
• Utilized CuO NPs to convert H2S into CuS, minimizing electrochemical interference.
• Employed an ODA layer to shield against electrical double-layer (EDL) potential fluctuations.
• Synchronously tracked neuronal activity and H2S-interference-free AA release dynamics during CSD in rat cortex.

Main Results:

• The developed sensor achieved highly selective AA assay without H2S interference.
• Ascorbic acid (AA) release was temporally coincident with neuronal suppression during CSD.
• Higher KCl concentrations prolonged both AA elevation and neuronal silencing.
• Repeated CSD induction showed cumulative effects, including decreased induction threshold and increased AA elevation magnitude and recovery time.

Conclusions:

• Ascorbic acid (AA) can serve as a real-time marker for cortical spreading depression (CSD).
• AA dynamics reflect the injury burden imposed by CSD events.
• The novel shielding strategy enables interference-free in vivo AA monitoring.