Title : Simultaneous electrochemical determination of neurotransmitters using polypyrrole nanocomposites-modified titanium nitride electrodes
Abstract:
The detection of neurochemical signals is essential for understanding brain function and diagnosing neurological disorders. The ability to accurately detect neurotransmitters can lead to significant advancements in diagnosing and managing conditions such as depression, Parkinson's disease, and epilepsy. Electrochemical sensors provide a promising approach due to their sensitivity, specificity, and rapid response times. However, challenges arise from interfering species with higher concentrations and oxidation potentials similar to those of the target analytes can compromise sensor’s performance and accuracy.
To address these challenges, we developed a highly sensitive and high-performance electrochemical sensor for neurotransmitters based on titanium nitride (TiN) electrodes modified with polypyrrole (PPy) nanocomposites, specifically targeting the simultaneous detection of dopamine and serotonin. The modified TiN sensors were fabricated via a physical vapour deposition (PVD) technique, followed by physical deposition of an organic material and the electrochemical polymerization of pyrrole monomer solution. The PPy coating was synthesized on chemically treated TiN surfaces through various electrochemical deposition methods. We explored different concentrations of pyrrole monomer/ sodium dodecyl sulphate (SDS) to enhance the electrode's conductivity and electrochemical properties. The findings revealed that the presence of both compositions has a synergistic effect on the performance-boosting of the sensor and increased the anodic peak currents up to fourfold compared to bare TiN electrode. The results suggest that by precisely controlling deposition parameters, it is possible to achieve over 80% enhancement in electrode’s conductivity. Furthermore, various morphologies, from uniform hole-based structures to clusters of nanoparticles can be obtained. Calibration curves were established using differential pulse voltammetry (DPV) measurements, demonstrating a strong linear relationship between the concentrations of the analytes (i.e. dopamine and serotonin) and the corresponding current responses. These results highlight the potential of our sensor design for effective neurotransmitter monitoring in clinical applications.
