Sensor for Detection of Formaldehyde Gas


Project ID: D2021-02


Formaldehyde (CH2O) is a volatile organic compound (VOC) that has been classified as one of the most toxic carcinogens by both the World Health Organization (WHO) and the United States Environmental Protection Agency (US EPA).  Since formaldehyde gas can damage the nervous and immune systems, the WHO has set a maximum of 30 min of exposure to 0.08 ppm of formaldehyde gas to minimize any health issues. Detection of VOCs is important in many different areas such as the petroleum industry, water separation processes, and indoor or outdoor air pollution from fuel combustion and paints.  Conventional methods, such as gas chromatography and spectrophotometry, usually require large high-end equipment with practical limitations of mobility, high energy consumption, and inaccuracy.  Therefore, there is a need for cost-effective, portable, and accurate sensors for detecting VOCs especially in the gas phase.

Invention Summary:

Researchers at the University of Toledo has developed a state-of-the-art molybdenum oxide (MoOx)-based portable electrochemical sensor for the detection of formaldehyde in the gas phase and the nanoclusters grafted to MoOx resulted in the improved conductivity of the sensor. The novel sensor has excellent sensitivity being able to detect formaldehyde in a gas phase at a concentration as low as about 0.005 ppm. The novel nanocomposite gas sensor demonstrated a greater sensor response to electrical current changes when the formaldehyde concentration increased. The sensor is highly selective to formaldehyde demonstrating 25 - 300 times greater current changes with formaldehyde than other volatile organic compounds such as acetone, methanol, ethanol, and isopropanol. In addition, the electrochemical interaction between the sensor and formaldehyde shows a unique phase angle shift at 0.05-0.06 Hz with electrochemical impedance spectroscopy (EIS), whereas other VOCs show no phase angle shift.


Detection of Formaldehyde Gas.


  • Detection at concentration as low as about 0.005 ppm
  • High sensitivity and selectivity (due to highly dispersed MoOx nanoparticles).
  • Efficient at room temperature.
  • The nanocomposite does not contain a noble metal.
  • Effective EIS at low frequencies, 0.04 - 0.1 Hz.
  • Prototype is available for testing.

IP Status:  Patent Pending

Patent Information:
For Information, Contact:
Stephen Snider
AVP Tech Transfer
The University of Toledo
419 530 6225
Ana Alba Rubio
Dong Shik Kim
Haidar Alolaywi
Formaldehyde Gas
Gas Sensor
Molybdenum Oxide
Volatile Organic Compound (VOC)