Tag Archives: nanozymes

A nanozyme that is organic, non-toxic, environmentally friendly, cost effective, and can detect the presence of glyphosate

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An October 16, 2023 University of Illinois news release (also on EurekAlert), describes research into developing a tool to detect the presence of the agricultural herbicide, glyphosate, Note: Links have been removed,

Nanozymes are synthetic materials that mimic the properties of natural enzymes for applications in biomedicine and chemical engineering. They are generally considered too toxic and expensive for use in agriculture and food science. Now, researchers from the University of Illinois Urbana-Champaign have developed a nanozyme that is organic, non-toxic, environmentally friendly, and cost effective. In a newly published paper, they describe its features and its capacity to detect the presence of glyphosate, a common agricultural herbicide. Their goal is to eventually create a user-friendly test kit for consumers and agricultural producers.

“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),” explained Dong Hoon Lee, a doctoral student in the Department of Agricultural and Biological Engineering (ABE), part of the College of Agricultural, Consumer and Environmental Sciences (ACES) and The Grainger College of Engineering at U. of I.

These nanozymes mimic the activity of peroxidase, an enzyme that catalyzes the oxidation of a substrate by using hydrogen peroxide as an oxidizing agent. They provide higher stability and lower cost than natural peroxidase, and they are widely used in biomedical research, including biosensors for detection of target molecules in disease diagnostics.

“Traditional nanozymes are created from inorganic, metal-based materials, making them too toxic and expensive to be directly applied on food and agriculture,” Lee said.

“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.”

The researchers also implemented a colorimetric sensing system integrated with the OC nanozyme for target molecule detection. Colorimetric assays, an optical sensing method, use color intensity to provide an estimated concentration of the presence of specific molecules in a substance, such that darker or lighter color indicates lower or higher quantity of target molecules. The organic-compound nanozyme performed on par with nanozymes typically used in biosensing applications within their kinetic profile with molecule detection performance.

“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,” said Mohammed Kamruzzaman, assistant professor in ABE and co-author on the study.

Lee and Kamruzzaman applied the OC nanozyme-based, colorimetric sensing platform to detect the presence of glyphosate, a widely used herbicide in the agricultural industry. They performed colorimetric assays in solutions containing varying concentrations of glyphosate, finding the organic nanozyme was able to successfully detect glyphosate with adequate accuracy.

“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,” Kamruzzaman stated. “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.”

The researchers are also working on developing additional nanozymes, envisioning these environmental-friendly materials hold great potential for a wide range of applications.

Here’s a link to and a citation for the paper,

Organic compound-based nanozymes for agricultural herbicide detection by Dong Hoon Lee and Mohammed Kamruzzaman. Nanoscale, 2023,15, 12954-12960 First published July 28, 2023

This paper is open access once you have created your free account.

An artificial enzyme uses light to kill bacteria

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An April 4, 2018 news item on ScienceDaily announces a light-based approach to killing bacteria,

Researchers from RMIT University [Australia] have developed a new artificial enzyme that uses light to kill bacteria.

The artificial enzymes could one day be used in the fight against infections, and to keep high-risk public spaces like hospitals free of bacteria like E. coli and Golden Staph.

E. coli can cause dysentery and gastroenteritis, while Golden Staph is the major cause of hospital-acquired secondary infections and chronic wound infections.

Made from tiny nanorods — 1000 times smaller than the thickness of the human hair — the “NanoZymes” use visible light to create highly reactive oxygen species that rapidly break down and kill bacteria.

Lead researcher, Professor Vipul Bansal who is an Australian Future Fellow and Director of RMIT’s Sir Ian Potter NanoBioSensing Facility, said the new NanoZymes offer a major cutting edge over nature’s ability to kill bacteria.

Dead bacteria made beautiful,

Caption: A 3-D rendering of dead bacteria after it has come into contact with the NanoZymes.
Credit: Dr. Chaitali Dekiwadia/ RMIT Microscopy and Microanalysis Facility

An April 5, 2018 RMIT University press release (also on EurekAlert but dated April 4, 2018), which originated the news item, expands on the theme,

“For a number of years we have been attempting to develop artificial enzymes that can fight bacteria, while also offering opportunities to control bacterial infections using external ‘triggers’ and ‘stimuli’,” Bansal said. “Now we have finally cracked it.

“Our NanoZymes are artificial enzymes that combine light with moisture to cause a biochemical reaction that produces OH radicals and breaks down bacteria. Nature’s antibacterial activity does not respond to external triggers such as light.

“We have shown that when shined upon with a flash of white light, the activity of our NanoZymes increases by over 20 times, forming holes in bacterial cells and killing them efficiently.

“This next generation of nanomaterials are likely to offer new opportunities in bacteria free surfaces and controlling spread of infections in public hospitals.”

The NanoZymes work in a solution that mimics the fluid in a wound. This solution could be sprayed onto surfaces.

The NanoZymes are also produced as powders to mix with paints, ceramics and other consumer products. This could mean bacteria-free walls and surfaces in hospitals.

Public toilets — places with high levels of bacteria, and in particular E. coli — are also a prime location for the NanoZymes, and the researchers believe their new technology may even have the potential to create self-cleaning toilet bowls.

While the NanoZymes currently use visible light from torches or similar light sources, in the future they could be activated by sunlight.

The researchers have shown that the NanoZymes work in a lab environment. The team is now evaluating the long-term performance of the NanoZymes in consumer products.

“The next step will be to validate the bacteria killing and wound healing ability of these NanoZymes outside of the lab,” Bansal said.

“This NanoZyme technology has huge potential, and we are seeking interest from appropriate industries for joint product development.”

Here’s a link to and a citation for the paper,

Visible-Light-Triggered Reactive-Oxygen-Species-Mediated Antibacterial Activity of Peroxidase-Mimic CuO Nanorods by Md. Nurul Karim, Mandeep Singh, Pabudi Weerathunge, Pengju Bian, Rongkun Zheng, Chaitali Dekiwadia, Taimur Ahmed, Sumeet Walia, Enrico Della Gaspera, Sanjay Singh, Rajesh Ramanathan, and Vipul Bansal. ACS Appl. Nano Mater., Article ASAP DOI: 10.1021/acsanm.8b00153 Publication Date (Web): March 6, 2018

Copyright © 2018 American Chemical Society

This paper is open access.

Nanozymes as an antidote for pesticides

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Should you have concerns about exposure to pesticides or chemical warfare agents (timely given events in Syria as per this April 4, 2017 news item on CBC [Canadian Broadcasting News Corporation] online) , scientists at the Lomonosov Moscow State University have developed a possible antidote according to a March 8,, 2017 news item on phys.org,

Members of the Faculty of Chemistry of the Lomonosov Moscow State University have developed novel nanosized agents that could be used as efficient protective and antidote modalities against the impact of neurotoxic organophosphorus compounds such as pesticides and chemical warfare agents. …

A March 7, 2017 Lomonosov Moscow State University press release on EurekAlert, which originated the news item, describes the work in detail,

A group of scientists from the Faculty of Chemistry under the leadership of Prof. Alexander Kabanov has focused their research supported by a “megagrant” on the nanoparticle-based delivery to an organism of enzymes, capable of destroying toxic organophosphorous compounds. Development of first nanosized drugs has started more than 30 years ago and already in the 90-s first nanomedicines for cancer treatment entered the market. First such medicines were based on liposomes – spherical vesicles made of lipid bilayers. The new technology, developed by Kabanov and his colleagues, uses an enzyme, synthesized at the Lomonosov Moscow State University, encapsulated into a biodegradable polymer coat, based on an amino acid (glutamic acid).

Alexander Kabanov, Doctor of Chemistry, Professor at the Eshelman School of Pharmacy of the University of North Carolina (USA) and the Faculty of Chemistry, M. V. Lomonosov Moscow State University, one of the authors of the article explains: “At the end of the 80-s my team (at that time in Moscow) and independently Japanese colleagues led by Prof. Kazunori Kataoka from Tokyo began using polymer micelles for small molecules delivery. Soon the nanomedicine field has “exploded”. Currently hundreds of laboratories across the globe work in this area, applying a wide variety of approaches to creation of such nanosized agents. A medicine on the basis of polymeric micelles, developed by a Korean company Samyang Biopharm, was approved for human use in 2006.”

Professor Kabanov’s team after moving to the USA in 1994 focused on development of polymer micelles, which could include biopolymers due to electrostatic interactions. Initially chemists were interested in usage of micelles for RNA and DNA delivery but later on scientists started actively utilizing this approach for delivery of proteins and, namely, enzymes, to the brain and other organs.

Alexander Kabanov says: “At the time I worked at the University of Nebraska Medical Center, in Omaha (USA) and by 2010 we had a lot of results in this area. That’s why when my colleague from the Chemical Enzymology Department of the Lomonosov Moscow State University, Prof. Natalia Klyachko offered me to apply for a megagrant the research theme of the new laboratory was quite obvious. Specifically, to use our delivery approach, which we’ve called a “nanozyme”, for “improvement” of enzymes, developed by colleagues at the Lomonosov Moscow State University for its further medical application.”

Scientists together with the group of enzymologists from the Lomonosov Moscow State University under the leadership of Elena Efremenko, Doctor of Biological Sciences, have chosen organophosphorus hydrolase as a one of the delivered enzymes. Organophosphorus hydrolase is capable of degrading toxic pesticides and chemical warfare agents with very high rate. However, it has disadvantages: because of its bacterial origin, an immune response is observed as a result of its delivery to an organism of mammals. Moreover, organophosphorus hydrolase is quickly removed from the body. Chemists have solved this problem with the help of a “self-assembly” approach: as a result of inclusion of organophosphorus hydrolase enzyme in a nanozyme particles the immune response becomes weaker and, on the contrary, both the storage stability of the enzyme and its lifetime after delivery to an organism considerably increase. Rat experiments have proved that such nanozyme efficiently protects organisms against lethal doses of highly toxic pesticides and even chemical warfare agents, such as VX nerve gas.

Alexander Kabanov summarizes: “The simplicity of our approach is very important. You could get an organophosphorus hydrolase nanozyme by simple mixing of aqueous solutions of anenzyme and safe biocompatible polymer. This nanozyme is self-assembled due to electrostatic interaction between a protein (enzyme) and polymer”.

According to the scientist’s words the simplicity and technological effectiveness of the approach along with the obtained promising results of animal experiments bring hope that this modality could be successful and in clinical use.

Members of the Faculty of Chemistry of the Lomonosov Moscow State University, along with scientists from the 27th Central Research Institute of the Ministry of Defense of the Russian Federation, the Eshelman School of Pharmacy of the University of North Carolina at Chapel Hill (USA) and the University of Nebraska Medical Center (UNC) have taken part in the Project.

Here’s a link to and a citation for the paper,

A simple and highly effective catalytic nanozyme scavenger for organophosphorus neurotoxins by Elena N. Efremenko, Ilya V. Lyagin, Natalia L. Klyachko, Tatiana Bronich, Natalia V. Zavyalova, Yuhang Jiang, Alexander V. Kabanov. Journal of Controlled Release Volume 247, 10 February 2017, Pages 175–181  http://dx.doi.org/10.1016/j.jconrel.2016.12.037

This paper is behind a paywall.