3D-printed ‘Lab-on-a-Drone’ Assesses Air Pollutants in Real Time

This modified quadcopter drone can detect and analyze hydrogen sulfide gas while in the air. Credit: Adapted from Analytical Chemistry, 2023, DOI: 10.1021/acs.analchem.3c02719

Key points:

• Researchers developed an inexpensive “lab-on-a-drone” capable of measuring air pollutants and reporting results in real time.
• The measurement device accurately assessed hydrogen sulfide (H₂S) concentration on the ground, at 30 feet, and at 65 feet in the air at three different times during the day.
• In the future, the device can be adapted to detect other pollutants.

Polluted air can contribute to the development of asthma and other conditions, but it is difficult to measure pollutants and contaminants including hydrogen sulfide (H₂S). H₂S is a smelly byproduct of petroleum refineries and wastewater treatment plants that is an irritant that can be toxic.

Many air quality measurement devices are ground-based and unable to assess H₂S and other contaminants that drift away. Expensive satellites can be used at higher altitudes and unmanned drones have been used to gather samples in mid-air, but analyses were still performed on the ground with traditional instruments.

However, a new method, published in ACS’ Analytical Chemistry, utilized an inexpensive “lab-on-a-drone” that can sample H₂S gas in mid-air and report the results in real time.

Researchers used a 3D printer to manufacture a custom device that was then mounted to the bottom of a commercially available quadcopter drone. The device relies on the chemical reaction between H₂S and a green fluorescein mercuric acetate molecule. When excited by a blue LED light, the interaction results in a decrease in the green fluorescence intensity, which can be detected and quantified.

In testing, the drone was successful in assessing H₂S concentration in the air, on the ground, at 30 feet, and at 65 feet in the air at three separate times during the day. The detection device attached to the drone transmits the results via Bluetooth to a smartphone for real-time contaminant monitoring.  

The study authors say lab-on-a-drone can be adapted to detect pollutants other than H₂S in the future.