3D-Printed Potentiometric Multicells for Enhanced Analytical Performance of Solid Contact Ion-Selective Electrodes

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Materials Science

Background:

• Ion-selective electrodes (ISEs) sensitivity is governed by the Nernst equation.
• The cells connected in series (CCS) concept aimed to amplify ISE sensitivity but faced fabrication challenges.
• Previous CCS applications were limited by bulky electrodes and complex sensor manufacturing.

Purpose of the Study:

• To revive and modernize the overlooked cells connected in series (CCS) concept.
• To develop a miniaturized, modular, and easily manufacturable platform for potentiometric sensing.
• To enhance the sensitivity and detection capabilities of ion-selective electrodes.

Main Methods:

• Introduction of 3D-printed potentiometric multicells (3DP-PMCs) integrating solid-contact ISEs and solid-state reference electrodes.
• Utilizing 3D printing for reproducible and flexible fabrication of compact, interconnected architectures.
• Demonstration of slope multiplication and enhanced performance across narrow concentration intervals.

Main Results:

• 3DP-PMC platform achieved up to 8-fold slope multiplication, reaching sensitivities of 475 ± 12 mV dec⁻¹.
• The octuple-cell configuration enabled detection of 0.1 mM concentration changes (2% change).
• Enhanced performance was maintained across narrow concentration intervals, surpassing individual cell capabilities.

Conclusions:

• Successfully translated the CCS principle into a miniaturized, modular, and manufacturable 3D-printed format.
• 3DP-PMCs offer a practical solution for enhanced potentiometric sensing.
• This technology paves the way for integration into microfluidic, wearable, and point-of-care devices.