Nanozymes are synthetic materials with features that resemble those of natural enzymes and are used in biomedical and chemical engineering. They are typically viewed as being too costly and hazardous to be used in agricultural and food research. Now, scientists at the University of Illinois Urbana-Champaign have created a nanozyme that is organic, non-toxic, economical, and ecologically acceptable.
Dong Hoon Lee, a graduate student in agricultural and biological engineering. Image Credit: University of Illinois Urbana-Champaign
They detail its characteristics and ability to find glyphosate, a prevalent agricultural pesticide, in a recently published study. They want to eventually develop an easy-to-use test kit for consumers and farmers.
The word nanozyme is derived from nanomaterial and enzyme. Nanozymes were first developed about 15 years ago, when researchers found that iron oxide nanoparticles may perform catalytic activity similar to natural enzymes (peroxidase).
Dong Hoon Lee, Doctoral Student, Department of Agricultural and Biological Engineering, University of Illinois Urbana-Champaign
These nanozymes imitate the function of peroxidase, an enzyme that uses hydrogen peroxide as an oxidizing agent to catalyze the oxidation of a substrate. They are often utilized in biomedical research, including biosensors for the detection of target molecules in disease diagnostics, since they offer superior stability and a cheaper cost than natural peroxidase.
Lee added, “Traditional nanozymes are created from inorganic, metal-based materials, making them too toxic and expensive to be directly applied on food and agriculture. Our research group is pioneering the development of fully organic compound-based nanozymes (OC nanozymes) which exhibit peroxidase-like activities. The OC nanozyme follows the catalytic activity of the natural enzyme but is predominantly based on agriculture-friendly organic compounds, such as urea acting as a chelating-like agent and polyvinyl alcohol as a particle stabilizer.”
To detect target molecules, the researchers additionally combined a colorimetric sensing device with the OC nanozyme. Darker or lighter colors represent a lower or greater concentration of the target molecules, respectively, in colorimetric assays, an optical sensing technique that uses color intensity to provide an estimated concentration of the presence of certain molecules in a sample.
The kinetic profile and molecular detection capabilities of the organic-compound nanozyme were similar to nanozymes often utilized in biosensing applications.
Traditional nanozymes come with a host of issues: toxicity, lengthy degradation, and a complex production process. In contrast, our nanozyme is quicker to produce, cost-effective, non-toxic, and environmentally friendly.
Mohammed Kamruzzaman, Study Co-Author and Assistant Professor, Department of Agricultural and Biological Engineering, University of Illinois Urbana-Champaign
The OC nanozyme-based, colorimetric sensing technology was utilized by Lee and Kamruzzaman to identify the presence of glyphosate, a common herbicide in the agricultural sector. They used colorimetric tests in solutions with different glyphosate concentrations and discovered that the organic nanozyme was capable of accurately and successfully detecting glyphosate.
Kamruzzaman added, “There is an increasing demand for testing pesticide or herbicide presence in agricultural products to protect human and crop health. We want to develop an OC nanozyme-based, point-of-use testing platform for farmers or consumers that they can apply in the field or at home. People would obtain a test kit with a substance to mix with their sample, then take a picture and use an app on their phone to identify the color intensity and interpret if there is any glyphosate present. The ultimate goal is to make the test portable and applicable anywhere.”
Scientists are also focusing on creating more nanozymes since they believe that these eco-friendly substances have a lot of promise for use in a variety of applications.
Journal Reference
Lee, D. H., et al. (2023) Organic compound-based nanozymes for agricultural herbicide detection. Nanoscale. doi:10.1039/D3NR02025H
Source: https://illinois.edu/