Ammonia detection: A pathway towards potential point-of-care diagnostics

Developing a Chemiresistive Gas Sensor Array for Simultaneous Detection of Ammonia and Carbon Dioxide Gases

“…In an applied scenario such as atmosphere packaging, the expected CO 2 range is from 5000 to 40,000 ppm (5–40% CO 2 gas) . Similarly, for NH 3 detection, a concentration below 1 ppm plays a vital role in differentiating mouth-exhaled NH 3 concentrations for specific disease detection . Overall, the prototype developed in this study has the capability of monitoring CO 2 and NH 3 gases for potential food quality, and medical diagnostic applications due to its robustness, low limit of detection, and ability to selectively monitor CO 2 and NH 3 gases in complex wet environments.…”

“…Chemiresistive gas sensors have become increasingly popular owing to their unique characteristics, including their easy manufacturing process, portability, and tunability for different applications. , They have been considered for food quality and safety, monitoring exhaled breath for diagnosis of Helicobacter pylori (H. pylori) infection, and detection of environmental contaminants . In the development of chemiresistive gas sensors, it is crucial to assess the ability of the system to selectively identify the target analyte in the presence of other interfering gases and volatile organic compounds that may share similar functional groups .…”

Chemiresistive Sensor for Enhanced CO2 Gas Monitoring

“…Nonetheless, a significant drawback of these sensors is their inability to function effectively when subjected to high levels of relative humidity (RH) (above 60% RH). 17 Additionally, they require elevated operating temperatures (ranging from 300 to 700 °C) and have a relatively large physical footprint. 18,19 Another limitation is that many MOSbased CO 2 sensors tend to detect other interfering gases, such as ammonia, in conjunction with the intended target, CO CO 2 gas monitoring is required at room temperature within complex moist environments, such as in food packaging.…”

“…Among the various CO 2 sensors developed based on chemiresistive principles, the most notable ones are the gas sensors that utilize metal oxide semiconductors (MOS). , These sensors are favored due to their convenient manufacturing process and their ability to exhibit rapid response and recovery times. Nonetheless, a significant drawback of these sensors is their inability to function effectively when subjected to high levels of relative humidity (RH) (above 60% RH) . Additionally, they require elevated operating temperatures (ranging from 300 to 700 °C) and have a relatively large physical footprint. , Another limitation is that many MOS-based CO 2 sensors tend to detect other interfering gases, such as ammonia, in conjunction with the intended target, CO 2 .…”