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Fully 3D-printed solid-contact potentiometric sensor for sodium determination
Sarah Farahani1, Kaylie A McCracken1, Hannah N Medley1
1Department of Chemistry, Washington State University, Pullman, WA, 99164, United States.
Biosensors & Bioelectronics
|August 14, 2025
Summary
This study introduces the first fully 3D-printed solid-contact ion-selective electrode for sodium (Na+) sensing. This novel 3D-printed Na+-ISE offers high stability and selectivity for biological fluid analysis.
Area of Science:
- Electroanalysis
- Materials Science
- Sensor Technology
Background:
- Potentiometric sensors, particularly ion-selective electrodes (ISEs), are crucial for analyzing ions in various matrices.
- Traditional fabrication methods for ISEs can be complex and costly, limiting widespread application.
- Solid-contact (SC) ISEs offer advantages over traditional liquid-junction designs, but their fabrication often requires specialized techniques.
Purpose of the Study:
- To design and fabricate the first fully 3D-printed solid-contact ion-selective electrode (3Dp-SC-ISE) for sodium ion (Na+) detection.
- To explore the utility of 3D-printing technologies in creating advanced electroanalytical devices.
- To demonstrate the tunability of sensor properties through 3D-printing parameters.
Main Methods:
- Fabrication of Na+-selective membranes using stereolithography.
- Construction of carbon-infused polylactic acid transducers via fused-deposition modeling.
- Characterization of sensor performance, including stability, response linearity, Nernstian behavior, selectivity, and limit of detection.
- Validation of the sensor's performance in human saliva samples.
Main Results:
- The developed 3D-printed Na+-ISE exhibited high stability with minimal drift (∼20 μV/hour).
- The sensor demonstrated a linear and Nernstian response (57.1 mV/decade) for Na+ across physiologically relevant concentrations (240 μM–250 mM).
- Excellent selectivity for Na+ was observed in the presence of common interfering ions, with a limit of detection of 0.0024 mM.
Conclusions:
- Fully 3D-printed solid-contact potentiometric sensors are feasible and offer significant advantages in electroanalysis.
- 3D-printing enables precise control over sensor design and material properties, leading to enhanced performance.
- This technology facilitates the mass production of low-cost, highly functional ISEs with broad applicability in clinical and environmental monitoring.
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