An electrochemical acetylcholine sensor based on lichen-like nickel oxide nanostructure

Area of Science:

• Electrochemistry
• Nanomaterials Science
• Analytical Chemistry

Background:

• Nickel oxide nanostructures are promising for electrochemical sensing applications.
• Developing efficient and stable sensors for neurotransmitters like acetylcholine is crucial.

Purpose of the Study:

• To synthesize and characterize a lichen-like nickel oxide nanostructure.
• To fabricate a novel electrochemical sensor for acetylcholine (ACh) detection using this nanostructure.
• To investigate the electrocatalytic oxidation of ACh and compare its efficiency with other nickel nanostructures.

Main Methods:

• Synthesis and characterization of lichen-like nickel oxide nanostructure.
• Modification of carbon paste electrode and sensor fabrication.
• Electrochemical techniques including cyclic voltammetry, steady-state polarization, and chronoamperometry.
• Hydrodynamic amperometry for ACh determination.

Main Results:

• The lichen-like nickel oxide nanostructure exhibited superior electrocatalytic efficiency for ACh oxidation compared to micro- and nanoparticles.
• Detailed mechanistic and kinetic studies (catalytic rate constant, charge transfer coefficient, diffusion coefficient) were performed.
• A sensitive hydrodynamic amperometry method achieved a sensitivity of 392.4 mA M⁻¹ cm⁻² and a limit of detection of 26.7 μM for ACh.

Conclusions:

• The developed sensor offers a simple, enzyme-free, and reagent-free approach for ACh detection.
• The sensor demonstrates high electrocatalytic activity, excellent sensitivity, long-term stability, and antifouling properties.
• Lichen-like nickel oxide nanostructures represent a highly effective material for advanced electrochemical sensing platforms.