Screen-printed electrodes: a whole electrochemical cell on a disposable strip
Updated: 1 day ago
A classic electrochemical cell needs a glass vessel, three separate electrodes, polishing, cleaning and several millilitres of solution. A screen-printed electrode (SPE) puts the whole cell on a small strip that fits between two fingers and needs only a single drop of sample. That is why SPEs have become a workhorse of portable and on-site electroanalysis.
What is printed on the strip?
SPEs are made by thick-film deposition: conductive and insulating inks are pushed through a patterned mesh onto a ceramic or plastic substrate, layer by layer. Carbon, silver, gold and platinum inks are common choices, so the electrode material can be matched to the application.
Working electrode (WE): usually the central disc, often carbon or gold, where the target molecule reacts.
Counter electrode (CE): an arc around the working electrode that closes the circuit.
Reference electrode (RE): typically printed from Ag/AgCl ink to provide a stable reference potential.
Tracks, contacts and insulation: silver tracks connect the three electrodes to contact pads that plug into a portable potentiostat, while an insulating layer defines the exact area exposed to the sample.
Why scientists like them
If you have seen a home glucose meter, you already know the idea: insert a strip, add a drop, read the result. SPEs bring the same convenience to the analytical laboratory and to the field.
Low cost and mass production: printing many identical electrodes at once keeps the price per strip low and the geometry consistent.
Small sample volumes: one drop can cover the whole cell, which matters for precious biological samples.
Disposable: a fresh surface for every measurement avoids carry-over and time-consuming cleaning.
Portable: combined with a pocket-sized potentiostat, SPEs allow rapid, on-site and real-time measurements in healthcare, food and environmental monitoring.
A platform for modification
The working electrode of an SPE is also a convenient base for building more advanced sensors. Its surface, or the ink itself, can be modified with nanomaterials to increase sensitivity, or coated with recognition layers such as enzymes, antibodies, aptamers or molecularly imprinted polymers to improve selectivity. Because every strip is single-use, reproducibility between strips and batches still needs to be checked during method validation.
Key takeaways
An SPE contains a complete three-electrode cell printed on one disposable strip.
Low cost, small sample volume and portability make SPEs ideal for on-site analysis.
The working electrode can be modified with nanomaterials or recognition layers for better performance.
SPEs at SAOnS Lab
At SAOnS Lab, screen-printed electrodes are part of our toolbox for developing sensors for drugs, biomarkers and contaminants that can be used outside the central laboratory. One example from our group combines graphene-based gel electromembrane extraction with a modified screen-printed carbon electrode to detect the antibiotic streptomycin in honey samples (Pengsomjit et al., 2024).
Where would an on-site electrochemical test make the biggest difference in your field? Contact us and tell us.
References
Singh, S., Wang, J., Cinti, S., et al. (2022). Review—An overview on recent progress in screen-printed electroanalytical (bio)sensors. ECS Sensors Plus, 1(2), 023401. https://doi.org/10.1149/2754-2726/ac70e2
Paimard, G., Ghasali, E., Baeza, M., et al. (2023). Screen-printed electrodes: Fabrication, modification, and biosensing applications. Chemosensors, 11(2), 113. https://doi.org/10.3390/chemosensors11020113
Pengsomjit, U., Alahmad, W., Varanusupakul, P., et al. (2024). Graphene-based gel electromembrane extraction coupled with modified screen-printed carbon electrode for detecting streptomycin in honey samples: Greener strategy for food analysis. Talanta, 268, 125334. https://doi.org/10.1016/j.talanta.2023.125334
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