Nanozymes are synthetic materials that have enzyme-like catalytic properties, and they are broadly used for biomedical purposes, such as disease diagnostics. However, inorganic nanozymes are generally toxic, expensive, and complicated to produce, making them unsuitable for the agricultural and food industries. A University of Illinois Urbana-Champaign research team has developed organic-material-based nanozymes that are non-toxic, environmentally friendly, and cost effective. In two new studies, they introduce next-generation organic nanozymes and explore a point-of-use platform for molecule detection in agricultural products.
- Marianne Stein
"The first generation of organic-compound-based (OC) nanozymes had some minor drawbacks, so our research group worked to make improvements. The previous OC nanozymes required the use of particle stabilizing polymers having repeatable functional groups, which assured stability of the nanozyme's nanoscale framework, but didn't achieve a sufficiently small particle size," said lead author Dong Hoon Lee, who completed his Ph.D. from the Department of Agricultural and Biological Engineering (ABE), part of the College of Agricultural, Consumer and Environmental Sciences and The Grainger College of Engineering at the U. of I.
In the new iteration, they used a core amino acid (L- alanine) and polyethylene glycol as constituent materials and a novel particle synthesis technique that allowed them to bring the particle size down to less than 100 nanometers. This nanozyme resembles the physical framework and mimics the catalytic activity of target enzymes.
In the first study, the researchers showed these organic (OA) nanozymes combined with a colorimetric sensing platform can successfully detect the presence of histamine in food products.
"We used this analytic method on spinach and eggplant, which are among the top vegetables with a high concentration of histamine, and we obtained an affordable analytic performance profile. We were able to show that our system doesn't just work in the lab, it has the potential to be utilized for real-world applications as a cost-effective molecule sensing system for food and agriculture," Lee said.
In another study, they further refined the novel organic (OM) nanozyme production process and developed an integrated, colorimetric point-of-use platform that enables rapid detection of agricultural and biological molecules without a laboratory environment.
"Conventional detection methods are based on laboratory analysis, but it would be helpful to have a portable molecule sensing system for the agricultural and food environment, similar to point-of-care systems such as in-home COVID tests," Lee said.
The researchers first applied the system to detecting the presence of glyphosate, a common agricultural herbicide. Next, they used the enzyme-cascade reaction method to detect glucose, which is a common biological molecule. In both cases their system showed decent analytic sensitivity, and they were able to obtain accurate results within a few minutes.
"To complete this molecule sensing task at home, you need a Smartphone image-processing app integrated with an OM-nanozyme-based colorimetric sensing platform. Users may add liquid food samples to a liquid solution, then test with a small paper microfluidic strip for the detection procedure. If the strip changes color to green, you'll know catalytic activity occurs, and based on the color intensity, the sample may contain the target molecule (in this case, glyphosate or glucose). Then users can take a picture with their phone, and the app uses an algorithm to convert the color image to an estimated concentration of target molecules," said Mohammed Kamruzzaman, assistant professor in ABE and co-author on the study.
"Our research shows that organic-material-based nanozymes demonstrate strong enzyme-like catalytic performance, while offering a biodegradable, sustainable alternative to conventional inorganic nanozymes, making them suitable for use in agriculture, food safety, and further biological fields," Lee concluded.
The first paper, "Amino acid-based, sustainable organic nanozyme and integrated sensing platform for histamine detection," is published in Food Chemistry [DOI: 10.1016/j.foodchem.2025.142751].
The second paper, "Consolidated sustainable organic nanozyme integrated with Point-Of-Use sensing platform for dual agricultural and biological molecule detection," is published in Chemical Engineering Journal [DOI: 10.1016/j.cej.2025.159560]
Research support was provided by ITG (Imaging Technology Group), Beckman Institute, Material Research Laboratory, High Throughput Screening Facility, EPR laboratory, Mass Spectrometry Lab and Integrated Bioprocessing Research Laboratory at the University of Illinois at Urbana-Champaign.
