Biodegradable Device Monitors Levels of Pesticides in Fruit, Vegetables

This aerial photograph taken on Oct 31, 2022 shows a farmer spraying pesticide to a crop of cabbage cultivated in his field on the outskirts of Bengaluru. (AFP)
This aerial photograph taken on Oct 31, 2022 shows a farmer spraying pesticide to a crop of cabbage cultivated in his field on the outskirts of Bengaluru. (AFP)
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Biodegradable Device Monitors Levels of Pesticides in Fruit, Vegetables

This aerial photograph taken on Oct 31, 2022 shows a farmer spraying pesticide to a crop of cabbage cultivated in his field on the outskirts of Bengaluru. (AFP)
This aerial photograph taken on Oct 31, 2022 shows a farmer spraying pesticide to a crop of cabbage cultivated in his field on the outskirts of Bengaluru. (AFP)

Researchers at the University of São Paulo (USP) and the Federal University of Viçosa (UFV) in Brazil have developed a sustainable sensor that can be placed directly on the surface of a vegetable or fruit to detect the presence of pesticides.

The device has the potential to help ensure food safety in a world that increasingly suffers from a shortage of food and the environmental and health problems caused by excessive use of agrochemicals. The results of the study were published in the journal Biomaterials Advances.

Pesticides are widely used to raise crop yields and are typically applied by spraying, but only 50% reach their target. The rest ends up in soil, groundwater, surface water, raw drinking water, wastewater and food products.

Monitoring of pesticide levels in water, soil and food is therefore essential to prevent contact between these toxic substances and the public via the skin, lungs or digestive system.

The researchers explained that the tools most often used for this purpose are chromatographic techniques (consist of separating and defining chemical compounds), which are effective but have drawbacks such as the need for pretreatment of samples, expensive equipment and qualified laboratory specialists, as well as the long time taken to complete the analysis. The unsafe residues produced by organic solvents are also a significant problem under present-day conditions.

As an alternative, electrochemical sensors can combine affordability, rapid detection, large-scale production, convenience, ease of use, high selectivity and in situ pesticide detection.

“Our invention has all these features. The analysis is performed directly on the surface of fruit, vegetables or leaves. It is made of cellulose acetate, a material derived from wood pulp,” said Paulo Augusto Raymundo-Pereira, co-author of the study.

“Instead of the usual materials, which are environmentally unsustainable and take a long time to degrade, such as ceramics or plastic polymers derived from petroleum, we used cellulose acetate, a material derived from plants that has little impact on the environment and disintegrates completely in 340 days or less depending on local conditions. It also has appropriate characteristics, including low cost, portability and flexibility,” he explained.

The researchers carried out laboratory tests in which a pesticide solution was sprayed on lettuce and tomatoes in a simulation of real-world use. The sensor was then directly attached to the lettuce and tomatoes, and measurements showed a level of detection compatible with those obtained with the sensor material most frequently used for this purpose.

The technology can be useful for sanitary surveillance agencies worldwide, farmers, as well as sellers of organic produce to certify absence of pesticides.



Prince William Begins a Visit to South Africa That Focuses on Climate and the Environment

Britain's Prince William, the Prince of Wales attends the "Homelessness: Reframed" exhibition at the Saatchi Gallery, Sept. 5, 2024 in London. (Chris Jackson/Pool Photo via AP, File)
Britain's Prince William, the Prince of Wales attends the "Homelessness: Reframed" exhibition at the Saatchi Gallery, Sept. 5, 2024 in London. (Chris Jackson/Pool Photo via AP, File)
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Prince William Begins a Visit to South Africa That Focuses on Climate and the Environment

Britain's Prince William, the Prince of Wales attends the "Homelessness: Reframed" exhibition at the Saatchi Gallery, Sept. 5, 2024 in London. (Chris Jackson/Pool Photo via AP, File)
Britain's Prince William, the Prince of Wales attends the "Homelessness: Reframed" exhibition at the Saatchi Gallery, Sept. 5, 2024 in London. (Chris Jackson/Pool Photo via AP, File)

Britain's Prince William will speak with young environmentalists and local fishermen during a visit to South Africa starting Monday that will see his annual Earthshot Prize award $1.2 million in grants to five organizations for innovative environmental ideas.

The 42-year-old heir to the throne will also attend a global wildlife summit and spend time at a sea rescue institute during his four days in Cape Town, with the centerpiece of his trip the Earthshot awards ceremony on Wednesday night.

He'll use the visit to highlight other issues close to his heart, like the work of rangers on the frontline of conservation efforts, officials said.

William, the Prince of Wales, last visited Africa in 2018, but he has a strong connection to the continent. William traveled to Africa as a boy after the death of his mother, Princess Diana, in a Paris car crash in 1997. He and his wife, Kate, got engaged at a wildlife conservancy in Kenya in 2010. And he said he came up with the idea for the Earthshot awards while in Namibia in 2018.

"Africa has always held a special place in my heart as somewhere I found comfort as a teenager, where I proposed to my wife, and most recently as the founding inspiration behind the Earthshot Prize," William said in a statement ahead of his visit.

Kate, Princess of Wales, and their children Prince George, Princess Charlotte and Prince Louis are not traveling to South Africa. Kate, 42, only recently returned to some public duties after completing treatment for an undisclosed type of cancer.

William's trip follows soon after his brother Harry, the Duke of Sussex, visited South Africa and neighboring Lesotho last month for a youth charity he set up with a member of Lesotho's royal family.

William formed the Earthshot Prize through his Royal Foundation in 2020 to encourage new ideas to solve environmental problems and it launched in 2021. The first three awards ceremonies were held in Britain, the U.S. and Singapore. William said he wanted this year's awards to inspire young people involved in climate action across Africa, a continent of some 1.5 billion people that contributes the least to global warming but is especially vulnerable to climatic shocks.

The wider southern African region is currently experiencing its worst drought and hunger crisis in decades, with 27 million people severely affected, according to the United Nations.

The Earthshot prizes are awarded in five categories: protecting and restoring nature, clean air, reviving oceans, building a waste-free world and fixing the climate. This year's finalists include a company in Kenya that develops solar-powered systems for homes, a group in Ecuador that brings Indigenous communities together to protect forests, and a conservation project in Kazakhstan that is saving the critically endangered Saiga antelope from extinction.

The awards ceremony will be held in a temporary, reusable dome that has been erected on a field next to a sports stadium in Cape Town. The 470-foot-long dome has hosted other events in South Africa and will be packed to be used again after the Earthshot prizes, organizers said.

While climate change and threats to the environment are at the center of William's visit, he will briefly break away from those topics to go to a high school in an underprivileged Cape Town neighborhood, where he's expected to join kids at a rugby practice.

Rugby is one of South Africa's most popular sports and the country's national team, the Springboks, are the reigning world champions. William is also a rugby follower.

“I can promise that you will see the Prince of Wales playing some rugby,” a Kensington Palace spokesperson said of the planned school visit.