Revolutionary NO Sensor for Highly Selective and Sensitive Gas Detection

A novel sensor leveraging WO3 and Cr2O3 for selective NO detection in harsh environments and breath analysis with high sensitivity at ppb levels.

The Need

There is a critical demand for advanced gas sensors capable of selectively detecting nitric oxide (NO) in diverse applications such as environmental monitoring, industrial processes, and medical diagnostics, particularly in challenging environments with interfering gases like carbon monoxide (CO).

The Technology

This innovative gas sensor utilizes a unique combination of tungsten trioxide (WO3) and chromium trioxide (Cr2O3) to create a diffuse p-n junction. The sensor operates by measuring changes in resistance, which are indicative of NO presence and concentration, even in the presence of high levels of CO. The WO3 and Cr2O3 regions are designed to interact with NO selectively, providing accurate readings down to parts-per-billion (ppb) levels. This configuration minimizes the influence of CO, making it ideal for applications where high selectivity and sensitivity are paramount. Additionally, a pre-calibrated database ensures precise NO concentration estimates from the measured resistance.

Commercial Applications

  • Environmental Monitoring: Detection of NO emissions from industrial sources and vehicular exhaust.

  • Medical Diagnostics: Breath analysis for diagnosing respiratory diseases.

  • Industrial Safety: Monitoring of NO levels in chemical plants and refineries.

  • Smart Buildings: Air quality control in HVAC systems.

  • Agricultural Monitoring: Assessing NO levels in greenhouse environments.


  • High Selectivity: Effectively discriminates NO from other gases, especially CO.

  • Sensitivity: Detects NO at ppb levels, ensuring precise measurements.

  • Robust Performance: Operates reliably in harsh environments.

  • Compact Design: Enables integration into portable and miniaturized devices.

  • Pre-calibrated Accuracy: Utilizes a pre-determined calibration curve for accurate NO concentration estimation.

Patent Protection

  • United States Patent No. 9,217,721

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