Sensors

Screen-printed electrodes (SPEs) explained: how they work and why they matter for sensing

VidyuthLabs · 14 October 2026

A screen-printed electrode (SPE) is a complete electrochemical cell printed onto a small strip. It is the reason electrochemical testing can leave the laboratory: cheap, disposable, consistent and ready to use.

What is on a screen-printed electrode

A typical SPE carries all three electrodes needed for a measurement on one substrate:

• Working electrode (WE): usually the central disc, where the measured reaction happens. Carbon, gold and platinum are common.
• Reference electrode (RE): often silver or silver/silver chloride, providing a stable potential.
• Counter electrode (CE): usually the same material as the working electrode, carrying the current.

Conductive tracks lead from the electrodes to contacts at the end of the strip, which plug into a potentiostat. An insulating layer leaves only the sensing area and the contacts exposed. A drop of sample on the sensing area is enough for a measurement.

How they are made

Conductive inks are pushed through a patterned mesh onto a ceramic, plastic or board substrate, layer by layer, then cured. Because it is a printing process, thousands of nearly identical electrodes can be produced at low cost. That consistency is what makes single-use sensors practical: every test starts on a fresh surface with known behaviour, and there is no polishing or cleaning between samples.

Electrode materials

• Carbon: inexpensive, with a wide potential window. A common base for modified sensors and for heavy-metal methods with bismuth films.
• Gold: well suited to arsenic and mercury analysis and to attaching biological receptors through thiol chemistry.
• Platinum: used for some oxidation reactions, such as hydrogen peroxide detection.

Why nanomaterial coatings matter

A bare electrode responds to many things. Coating the working electrode with a chosen nanomaterial, such as metal nanoparticles, carbon nanomaterials or metal oxides, can increase the active surface area, speed up electron transfer and favour the reaction you want to measure. The coating effectively turns a general-purpose electrode into a sensor for a specific analyte. Changing the coating changes the application, while the instrument stays the same.

Where SPE sensors are used

• Heavy metals in drinking water and wastewater (more on that here).
• Food safety screening, including adulterants such as formalin in fish.
• Soil and agriculture testing.
• Medical and biosensing, where the glucose test strip is the best-known example.
• Teaching and research electrochemistry.

Things to keep in mind

• Sample matrix: real samples contain salts, organics and particles that can interfere. Many methods need a simple preparation step such as buffering, filtering or extraction.
• Calibration: results are quantitative only with proper calibration or standard addition.
• Storage: coated sensors can have a shelf life and storage conditions that matter.

NanoX: our screen-printed sensors

NanoX is the VidyuthLabs family of gold ENIG screen-printed electrodes, with CE, WE and RE contacts on a single strip. Each NanoX sensor is coated with nanomaterials chosen for its application and clicks straight into the AnalyteX portable potentiostat.