Ion Transfer Voltammetry with an Electrochemical Pen

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Biomedical Engineering

Background:

• Ion-transfer voltammetry (ITV) is crucial for detecting redox-inactive species.
• Traditional ITV at the interface between two immiscible electrolyte solutions (ITIES) is limited by interface instability and specialized laboratory requirements.
• Developing user-friendly, portable ITV systems is essential for point-of-care applications.

Purpose of the Study:

• To create a stable, user-friendly electrochemical system for ion-transfer voltammetry.
• To enable point-of-care applications of ITV by overcoming traditional limitations.
• To demonstrate the versatility of the new system for analyzing various species and mixtures.

Main Methods:

• Development of a novel electrochemical cell combining a pen-like device with a gelled organic phase and a paper-supported aqueous phase.
• Utilizing paper-based sensing integrated with ion-transfer voltammetry.
• Employing paper chromatography for mixture analysis.

Main Results:

• The new system demonstrated stability and ease of assembly, making ITV more accessible.
• Successfully analyzed simple and ionophore-facilitated ion transfer, including proteins.
• Showcased preconcentration of species and analysis of mixtures.
• Native ion content in paper allowed measurements without added electrolytes.

Conclusions:

• The paper-based electrochemical system significantly enhances the practicality and accessibility of ion-transfer voltammetry.
• This innovation facilitates label-free electrochemical detection of nonredox-active species at points-of-need.
• The system holds promise for broadening the scope of point-of-care electrochemical diagnostics.