measure redox potential in microenvironments

Unisense RD-500With the tip size down to 10 µm, less than 5 seconds in response time, and 1 mV in resolution, the Unisense Redox microsensor offers a high quality research tool for reliable and fast measurements.

The microsensor construction makes it possible to use the Redox microsensor in a broad variety of research fields where non-destructive, fast and accurate measurements are required. The redox microelectrode is designed for research applications within:

  • Environmental sciences
  • Biomedical sciences
  • Biotechnology
  • Microbiology

Download Unisense Microsensors Brochure


microelectrode technology

The Redox electrode tip will develop an electrical potential relative to the reference electrode when both electrodes are immersed in the same solution and connected to a high-impedance millivolt-meter e.g. the Unisense pH/mV-Meter. This potential reflects the tendency of the solution to release or take up electrons; also called the Oxidation-Reduction Potential (ORP). The Unisense Redox microelectrode can be used for measurements in salinities from 0 to full ocean strength.

part numbers and outside tip diameter

  • Unisense pHmV-Meter_IMGRD-10: 8-12 µm
  • RD-25: 20-30 µm
  • RD-50: 40-60 µm
  • RD-100: 90-110 µm
  • RD-500: 400-600 µm
  • RD-MR: 400-600 µm
  • RD-N: 1.1 mm
  • RD-NP: 1.6 x 40 mm – needle sensor for piercing
  • RD-Eddy: 15-25 µm



Download Detailed Redox Spec Sheet



Download Redox Sensor Manual


reference electrode for redox microelectrodes

PageLines-UnisensepHREF-RM.jpgReference electrodes from Unisense are simple silver/silver-chloride open-ended electrodes designed to work with potentiometric microelectrodes (e.g. Unisense pH and Redox microelectrodes). For measurements with these sensors, it is important that the measuring sensor is in fluid contact with the reference. For most purposes this can be achieved with a large macro-reference. For some applications the sample is so small (e.g. a droplet) that the reference must be as small as the measuring microelectrode.

For laboratory use, Unisense provides a macro reference electrode from Radiometer Analytical. Our micro-sized reference electrodes are glass electrodes manufactured at Unisense. For in situ use, Unisense manufactures a pressure-compensated macro electrode.



Kristensen,E. et al (2011), Contrasting effects of the polychaetes Marenzelleria viridis and Nereis diversicolor on benthic metabolism and solute transport in sandy coastal sediment, Mar Ecol Prog Ser, 125 – 139, vol. 425

Schmidt,O. et al (2011), Novel [NiFe]-and [FeFe]-Hydrogenase Gene Transcripts Indicative of Active Facultative Aerobes and Obligate Anaerobes in Earthworm Gut Contents, Applied and Environmental microbiology, AEM – 05432, vol.

Vilalta,E. et al (2005), Structural heterogeneity in cyanobacterial mats is associated with geosmin production in rivers, Phycologia, 678 – 684, vol. 44


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