A Composite Semiconducting Metal Oxide Sensor for Detection and Analysis of Trace Ammonia

Sensing gases with high specificity and sensitivity in complex environments ranging from combustion processes to breath sensing using miniaturized solid-state electrochemical sensors.

The Need

Optimizing industrial operations, environmental monitoring, and disease diagnosis all require sensing of gases with high sensitivity and selectivity. In addition, decreasing the footprint of the sensor allows sensing to be done in size-constrained spaces. The global gas sensor market size was valued at $2.33 billion in 2020 and is expected to grow at a CAGR of 8.7% from 2021 to 2028. Important gases for combustion, environmental and human health include O2, CO, CO2, NH3 and NOx. Industrial, transport applications require sensors that can operate at high temperatures under harsh conditions. Sensor developments that address these needs can be expected to be highly profitable.

The Technology

A team of researchers at The Ohio State University, led by Dr. Prabir Dutta, have developed a comprehensive technology platform portfolio of gas sensors operational under mild as well as extraordinarily harsh conditions. The majority of these technologies are protected through issued patents with the balance being patent pending. These are solid-state sensors, using electrochemical principles to extract the sensor signal, with current, voltage, or resistance being the measured parameters. Dr. Dutta’s approach has been to combine ceramic materials, chemistry, and catalysis to obtain high sensitivity and selectivity. Novel ways of arranging the sensor form factor has also allowed for the extraction of signals from low concentration of gases, often in the ppb range. Because of the solid-state nature of the sensors, miniaturization is possible, thereby reducing costs. A portion of this sensor portfolio has response times of fractions of a second and are amenable for use in control systems via feedback monitoring.

Commercial Applications

The breadth of applications of these sensors is quite large, and depends on the specific sensor, its packaging, and footprint. These sensors can be used for environmental monitoring, process monitoring, and biomedical applications. In the attached document, we have identified these applications in a broad, general context, but will be pleased to discuss the potential for more specific applications depending on your needs.


  • Environmental/Industrial/Biomedical applications
  • Resistive mode
  • Operational temperature: 250-350°C
  • Sensitive over ppb to ppm levels (suitable biomarker for gastrointestinal disease diagnosis)
  • Interference from water vapor
  • Technology Readiness Level: TRL 3 (proof of concept established)

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