Monolithic Potentiometric Cell Using Fused Filament Fabrication

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Solid-contact electrodes have enabled decentralized ion sensing in health, environmental, and sports applications.
• A fully integrated, low-cost potentiometric cell has been a long-standing challenge.
• Previous methods often require complex manufacturing and assembly processes.

Purpose of the Study:

• To demonstrate the first monolithic, fully 3D printed potentiometric cell (3DP-PC) using fused filament fabrication (FFF).
• To integrate both ion-selective and reference electrodes into a single, disposable device.
• To assess the performance and applicability of the 3DP-PC for potassium ion detection.

Main Methods:

• Fabrication of a monolithic potentiometric cell using 3D printing (FFF) technology.
• Integration of ion-selective and reference electrodes within the 3D printed device.
• Potentiometric analysis of potassium ion concentration in various liquid samples.

Main Results:

• The 3DP-PC showed a linear response for potassium ions (10⁻⁵–10⁻¹ M) with a slope of 56.4 mV/decade and a limit of detection around 10⁻⁶ M.
• The device demonstrated good potential reproducibility (±4 mV) and minimal drift (short-term: 115 μV/h, long-term: -419 μV/h over 72 h).
• Successful and reliable detection of potassium ions in artificial interstitial fluid and sweat samples with near 100% recovery.

Conclusions:

• This work presents a significant milestone in creating fully 3D printed solid-contact potentiometric cells.
• The 3DP-PC offers a simplified, low-cost, and disposable platform for decentralized potentiometric sensing.
• The technology has the potential to revolutionize the on-demand production of sensing platforms, eliminating complex manufacturing and assembly.