E-Nose Developed to Detect Nanoplastics in the Air

To better understand the predominance of airborne plastics, researchers have devised a sensor that detects nanosized particles and identifies the types, amounts, and sizes of plastics using colorful carbon dot films.

Large plastic pieces can break down into nanosized particles that frequently find their way into the water and soil, a Phys.org report specified.

It remains unclear how nanoplastics affect human health, although animal studies suggest they are possibly hazardous.

The researchers are set to present their results today during the fall meeting of the American Chemical Society this year.

Plastic Materials Slowly Eroding

According to the study's principal investigator, Raz Jelinek, Ph.D., nanoplastics are a major concern if they are potentially leading to health problems.

Jelinek explained, "a simple, cost-oriented detector like ours could have huge implications," and one day warn people about the presence of nanoplastics in the air, enabling them to take action.

In a related report, Science Daily specified that millions of tons of plastics are produced and thrown away yearly.

Some plastic materials are slowly eroding while being used after they are disposed of, polluting the surroundings with micro- and nanosized particles.

E-Nose

Nanoplastics are very tiny and light that they can even float in the air, where they can be unknowingly breathed in by humans.

Animal studies suggest that ingesting and inhaling such nanoparticles may have damaging impacts, a similar Bioengineer.org report specified. As a result, it could be helpful to know the airborne nanoplastic pollution levels in the environment.

Previously, Jelinek's team at the Ben-Gurion University of the Negev developed an electronic nose or e-nose to monitor the presence of bacteria through adsorption and sense of a distinctive combination of gas vapor molecules emitted.

The researchers wanted to find out if this carbon-dot-based technology could be adapted to develop a sensitive nanoplastic sensor for continuously monitoring the environment.

Carbon Dots

Essentially, carbon dots are formed when a starting material containing plenty of carbon, like sugar or other organic matter, is heated at an average temperature for several hours.

Such a process can even be done using a conventional microwave. During heating, the carbon-containing material develops into colorful and frequently fluorescent nanoparticles known as "carbon dots."

More so, by changing the starting material, the carbon dots can have different surface properties that can attract numerous molecules.

To develop the bacterial e-nose, the researchers spread thin layers of different carbon dots onto small electrodes, each similar to the size of a fingernail.

Nanoplastics in the Air

The team utilized integrated electrodes with two sides with interspersed comb-like structures. Between these two sides, an electric field develops, and the stored charge is identified as capacitance.

Jelinek explained that when something happens to the carbon dots, either they adsorb gas molecules or pieces of nanoparticles, there is a change of capacitance, which can be easily measured.

The team also tested a proof-of-concept sensor for nanoplastics in the air, selecting carbon dots that would adsorb common plastic types such as polystyrene, polypropylene, and polymethyl methacrylate.

In studies, nanoscale plastic particles were aerosolized, enabling them to float in the air. And when electrodes coated with carbon-dot films were exposed to airborne nanoplastics, the team observed different indications for every type of material.

Senors Associated with Particle Size

Since the number of nanoplastics in the air is affecting the intensity of the signal produced, Jelinek is adding that at present, the sensor can report the amounts of particles from a specific type of plastic, either on top or, or under a predetermined concentration threshold.

In addition, when polystyrene particles of different sizes were aerosolized, the signal intensity of the sensor was directly associated with the size of the particles.

The researchers' next step is to find out if their system can differentiate the types of plastic in nanoparticle mixtures.

A report about the devised E-nose that can detect nanoplastics in the air is shown on the American Society Meeting Newsroom's YouTube video below:

Check out more news and information on Nanoparticles and Plastics in Science Times.