Electrochemical pH modulator coupled with Ni-based electrode for glucose sensing.

Area of Science:

• Electrochemistry
• Biosensors
• Materials Science

Background:

• Non-enzymatic electrochemical glucose detection often requires alkaline conditions, limiting practical applications.
• Nickel-based electrodes, effective for glucose oxidation, are typically hindered by their need for high pH environments.
• Existing methods face challenges in neutral pH media, restricting their use in biological samples.

Purpose of the Study:

• To develop a novel electrochemical system for glucose detection that operates effectively at neutral pH.
• To overcome the limitations of alkaline media requirements for nickel-based glucose sensors.
• To demonstrate a proof-of-concept for an enzyme-less, localized pH-modulating electrochemical detection method.

Main Methods:

• Utilized a 3D-printed prototype featuring a working nickel-based electrode and a parallel stainless-steel grid electrode.
• Applied a cathodic potential to the grid electrode to induce solvent reduction and generate localized hydroxide ions (OH⁻).
• Optimized electrodeposition of the nickel electrode and operating parameters for the electrochemical pH modulator.

Main Results:

• Achieved effective electrochemical detection of glucose at neutral pH by generating localized alkaline conditions near the nickel electrode.
• Demonstrated linear amperometric detection of glucose from 0.1 to 1 mM with a limit of detection of 73 μM under optimized conditions.
• Validated the proof-of-concept using a 3D-printed prototype, showcasing the feasibility of the localized pH modulation approach.

Conclusions:

• The proposed method successfully enables enzyme-less electrochemical glucose detection at neutral pH by localized pH modulation.
• This approach overcomes the limitations of alkaline media requirements for nickel-based electrodes.
• The technology holds promise for non-invasive glucose monitoring in real biological media.