Metallic nanostructures are increasingly used in fertilizers, pesticides and agroenvironmental technologies
Researchers from the Brazilian Center for Research in Energy and Materials (CNPEM) have conducted the first advanced molecular analysis of interactions between copper nanoparticles and tropical soils. The study revealed that the chemical characteristics of each type of soil can significantly alter how these structures behave, with potential to boost the accuracy and efficiency of agricultural practices. These results contribute to understanding the relationship between nanoscale materials and complex ecosystems, paving the way to develop more sustainable rural technologies and providing support for future regulatory and environmental evaluations. One new process that has already been developed from this study is already in the patent phase.
While metal oxide nanoparticles have increasingly been used for innovations in agricultural products, fertilizers, pesticides, sensors and environmental technologies, there is still little information about how they behave in tropical soils. The research assessed different types of soils, especially from the state of São Paulo (latosols) and the Amazon region (Amazonian black earths), as well as latosols treated with biochar made from sugarcane bagasse.
The lead author of the published study, Laís Fregolente, explains that “advances strengthen the integration between nanotechnology and agriculture by showing how the composition of soil organic matter influences how nanomaterials behave in the environment. This knowledge is essential to promote the safe and sustainable use of nanomaterials in agriculture, and guide the development of technologies suited to the reality of each soil type,” she stated.
According to CNPEM researcher Diego Martinez, who advised on the article (which was recently featured on the cover of Environmental Science Nano), nanoparticle behavior varies significantly according to soil type. “This is the first study to conduct a detailed molecular characterization of how copper nanoparticles interact in tropical soils, showing how soluble organic matter modifies the surface of these particles,” he noted. “The same material, the same nanoparticle, will behave differently in soils in São Paulo, soils in the Amazon or soil treated with biochar, because the organic matter present in each environment completely modifies the surface and reactivity of these particles.”
According to the researchers, understanding these interactions is essential in order to assess environmental impacts and develop safer applications for precision tropical agriculture. The study used advanced materials characterization techniques such as CNPEM’s synchrotron light, electronic and hyperspectral cryomicroscopy, and molecular analysis via high-resolution mass spectrometry to investigate the transformations nanoparticles undergo when they make contact with different types of tropical Brazilian soils. “When the nanoparticle comes into contact with organic matter in the soil, it forms an organic layer on the surface called a ‘molecular eco-corona’ that changes its behavior, mobility and toxicity,” said Martinez.
In addition to researchers from CNPEM, the project also included scientists from institutions in Brazil and abroad in the areas of nanotechnology, environmental chemistry and soil science. The authors include researchers from São Paulo State University (UNESP), the University of Birmingham (UK) and Old Dominion University (USA).
Based on these groundbreaking results and the experience acquired, the researchers developed a new technology that utilizes the molecular eco-corona concept. Copper nanoparticles were coated with organic matter to improve their adhesion on plant leaves, considering future production of innovative nanoagrochemicals for precision agriculture. The resulting technology is being patented and will be available for partnerships with companies through CNPEM’s innovation program.
