Drones lead the way in real

In a groundbreaking move, researcher João Flávio da Silveira Petruci and his team have sought to overcome these limitations. "We wanted to create an affordable 'lab-on-a-drone' that could not only sample the H2S gas while airborne but also analyze and report the data in real-time," Petruci commented.

To achieve this, the team employed 3D printing technology to craft a custom device, which they attached to the bottom of a commercially available quadcopter drone. This inventive device uses a unique chemical reaction involving H2S and a green-glowing fluorescein mercuric acetate molecule. An onboard blue LED light excites this interaction, causing a decrease in green fluorescence intensity that is detected and quantified.

Drone's detection system

One of the highlights of the technology is its high specificity. Other air pollutants do not affect the chemical reaction, often interfering with traditional monitoring methods. To test their innovation, the team took their drone to a wastewater treatment plant and sampled the air at various altitudes—ground level, around 30 feet, and 65 feet—at different times of the day.

The drone's detection system transmitted its findings via Bluetooth to a smartphone, allowing real-time monitoring. Interestingly, the researchers observed a noticeable increase in H2S concentration as the drone ascended, although the levels never exceeded the acceptable ambient range.

This groundbreaking development has been funded by the Coordination for the Improvement of Higher Education Personnel, the Research Support Foundation of the State of Minas Gerais, and the National Council for Scientific and Technological Development. Researchers believe the technology holds promise for adaptation to detect other air pollutants in the future, thereby providing a robust tool in the ongoing fight against environmental degradation.

While the "lab-on-a-drone" system marks a novel approach to air quality monitoring, it opens up a broader conversation on leveraging technology for sustainable environmental practices. The invention holds the potential to revolutionize air quality measurement and serves as a vital step toward a cleaner, healthier future.

The study was published in the journal Analytical Chemistry

Study abstract

The measurement of gaseous compounds in the atmosphere is a multichallenging task due to their low concentration range, long and latitudinal concentration variations, and sample interferents. Herein, we present a quadcopter drone deployed with a fully integrated 3D-printed analytical laboratory for H2S monitoring. Also, the analytical system makes part of the Internet of Things approach. The analytical method applied was based on the reaction between fluorescein mercuric acetate and H2S that led to fluorescence quenching. A 5 V micropump at a constant airflow of 50 mL min–1 was employed to deliver constant air into a flask containing 800 μL of the reagent. The analytical signal was obtained using a light-emitting diode and a miniaturized digital light detector. The method enabled the detection of H2S in the range from 15 to 200 ppbv, with a reproducibility of 5% for a sampling time of 10 min and an limit of detection of 9 ppbv. All devices were controlled using an Arduino powered by a small power bank, and the results were transmitted to a smartphone via Bluetooth. The proposed device resulted in a weight of 300 g and an overall cost of ∼50 USD. The platform was used to monitor the concentration of H2S in different intervals next to a wastewater treatment plant at ground and vertical levels. The ability to perform all analytical steps in the same device, the low-energy requirements, the low weight, and the attachment of data transmission modules offer new possibilities for drone-based analytical systems for air pollution monitoring.