Tag Archives: silver nanoparticles (AgNPs)

SERS (surface-enhanced Raman scattering) nanosensor in stretchable antimicrobial wrapper reveals food freshness in real time

Leave a reply

A November 26, 2025 news item on Nanowerk announces food science research from Korea, Note: A link has been removed,

Ensuring food quality is vital, but traditional monitoring tools such as ribotyping and PCR are slow, destructive, and impractical for widespread use. Scientists are now turning to surface-enhanced Raman scattering, or SERS, a technology that can analyze food in real time without damaging it.

A research team led by Associate Professor Ji-Hwan Ha of Hanbat National University in South Korea has developed a two-in-one solution. Their nanostructured SERS sensor, combined with a stretchable antimicrobial wrapper, directly monitors food while also helping to keep it fresh. The work was published in the journal Small (“SERS Sensor Integrated in Stretchable and Antimicrobial Wrapper for Food Quality Monitoring and Preservation”).

…

Caption: Researchers propose a novel nanostructured SERS sensor integrated into a stretchable and antimicrobial wrapper for food quality monitoring and preservation. Credit: Prof. Ji-Hwan Ha from Hanbat National University, Republic of Korea

A November 26, 2025 Hanbat National University (HBNU) press release on EurekAlert (also on PR Wire), which originated the mildly rewritten news item, provides a little more detail, Note: Links have been removed,

Food quality and safety are crucial. However, conventional food-monitoring methods, including ribotyping and polymerase chain reaction, tend to be destructive and lengthy. These shortcomings limit their potential for broad applications. In this regard, surface-enhanced Raman scattering (SERS) sensing, with real-time, non-destructive, and high sensitivity capabilities, is a highly promising alternative.

In a new breakthrough, a team of researchers, led by Associate Professor Ji-Hwan Ha from the Department of Mechanical Engineering, Hanbat National University, Republic of Korea, has developed a two-in-one nanostructured SERS sensor integrated into a stretchable and antimicrobial wrapper (NSSAW) that not only monitors food directly on the surface but also actively preserves it. Their novel findings were made available online on 29 May 2025 and have been published in Volume 21, Issue 38 of the journal Small on 25 September 2025 (Back Cover).

The proposed wrapper incorporates a nanostructured SERS sensor—Au [gold] nano-arrays loaded with Ag [silver] nanoparticles—that delivers up to 30.11-fold Raman enhancement, enabling real-time, non-destructive detection of nutritional components, including purines, proteins, lipids, and carotenoids, and even the pesticide thiram on meats, fish, and fruit. At the same time, the curcumin-thermoplastic polyurethane (TPU) electrospun wrapper shows strong antimicrobial efficacy of 99.99% against S. aureus and 99.9% against E. coli, helping extend shelf life.

Notably, NSSAW is highly stretchable and conformal, withstanding elongation of 716% and maximum stress of 52.3 MPa. The SERS layer is spontaneously integrated into it during fabrication via nanoimprint lithography, e-beam slanted deposition, and electrospinning with nanotransfer printing, indicating a practical route to scalable packaging.

“In cold-chain logistics and storage, the wrapper can help distributors decide when to ship and sell food by continuously tracking freshness and spoilage chemistry. In retail smart packaging, its stretchable, conformal, and biocompatible nature enables non-destructive, on-package checks of quality and nutrition markers—without any damage tofood—supporting point-of-sale quality automation and transparent date labeling. Thus, the real-world uses of our technology span the entire farm-to-fork chain,” says Prof. Ha.

Furthermore, NSSAW tracks spoilage progression over time by following the bacterial emission marker dimethyl disulfide, linking chemistry to freshness in a way that consumers and industry can interpret. This research is thus expected to open new horizons in monitoring the freshness and composition of human food.

“NSSAW can act as an on-food freshness indicator during consumer storage for home use and meal-kit delivery, linking chemical changes to easy-to-interpret signals over time. In addition, for high-value seafood and meats, quantitative tracking of purines such as hypoxanthine supports premium-grade verification and shelf-life decisions. Moreover, as active packaging, the curcumin-TPU, with its antimicrobial properties, complements sensing with preservation to extend shelf life in distribution and retail,” says Prof. Ha.

Over the next 5–10 years, packaging that both preserves food and continuously verifies its quality could move from pilot to mainstream. Leveraging the innovative technology presented in this study, retailers and consumers could rely on real-time, non-destructive quality signals instead of coarse date estimates—cutting waste, improving safety, and enabling smarter pricing and recalls.

***

About the institute

Established in 1927, Hanbat National University (HBNU) is a university in Daejeon, South Korea. As a leading national university in the region, HBNU strives to take the lead in solving problems in the local community and solidifying its cooperation with industries. The university’s vision is to become “an Innovation Platform University integrating local community, industry, academia, and research.” With its focus on practical education and regional impact, HBNU continually advances technological solutions grounded in creative thinking and real-world relevance.

Website: https://www.hanbat.ac.kr/eng/

About the author

Dr. Ji-Hwan Ha is an Associate Professor at the Department of Mechanical Engineering, Hanbat National University, Republic of Korea. His group is developing approaches to fabricate various composite nano/micro fiber using electrospinning process for wearable healthcare system and textile-based sensor. This research was conducted in collaboration with Professor Junseong Ahn’s group, Professor Sunae So’s group at Korea University, and Principal Researcher Jun-Ho Jeong’s group at the Korea Institute of Machinery and Materials.

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

SERS Sensor Integrated in Stretchable and Antimicrobial Wrapper for Food Quality Monitoring and Preservation by Ji-Hwan Ha, Jinhyeok Yang, Dodam Kim, Wonjoon Lee, Channyeong Yun, Soon Hyoung Hwang, Sohee Jeon, Jungrak Choi, Hakhyun Lim, Minki Kim, Dahong Kim, Su A Park, Joong-Won Song, Sunae So, Junseong Ahn, Jun-Ho Jeong. small Volume 21, Issue 38 September 25, 2025 2501808 First published online: 29 May 2025 DOI: https://doi.org/10.1002/smll.202501808

This paper is behind a paywall.

Fungus-produced silver nanoparticles could be used to prevent and treat COVID-19

Leave a reply

This May 6, 2025 news item on phys.org presents an intriguing possibility for COVID-19 prevention,

Silver nanoparticles produced by the fungus Trichoderma reesei could become important allies in the prevention and treatment of COVID-19. Tests carried out on hamsters showed that they not only inhibited the infection but also reduced the viral load in the lungs, easing inflammation in the rodents.

The study paves the way for the development of nasal sprays and other products to combat several viral diseases, such as HIV/AIDS, shingles and influenza.

…

A May 7, 2025 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) press release by Maria Fernanda Ziegler (also on EurekAlert but published May 6, 2025) provides more detail about the work,

Silver nanoparticles have been of interest to the pharmaceutical industry due to their high affinity for proteins. Depending on their shape and size, they attract and adhere to these molecules, inhibiting the progression of disease.

“Using computer analysis, we found that the silver nanoparticles produced in our laboratory bind to the spike protein, a kind of key that the SARS-CoV-2 virus uses to enter the host cells and replicate. In this way, they inhibit the entry of the virus into the cell by 50%,” says Roberto do Nascimento Silva, professor in the Department of Biochemistry and Immunology at the Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP) in Brazil and author of the study published in the journal Current Research in Biotechnology. 

Tests in hamsters have shown that the effects of the product may go beyond preventing COVID-19. “The most interesting thing is that the nanoparticles not only prevented the virus from entering the cells but were also able to improve acute lung inflammation, one of the worst complications of COVID-19, proving to be a viable treatment for the disease,” he says.

The researchers found that the silver nanoparticles prevented the activation of the inflammasome – a protein complex in cells responsible for the excessive immune response (cytokine storm) in severe COVID-19 – and the production of interleukin-1beta (IL-1β), a protein involved in the inflammatory response.

“We still need to deepen our understanding of which mechanism is involved in inhibiting the inflammatory response, but given the highly inflammatory nature of COVID-19, it can be inferred that silver nanoparticles reduce this process of cell damage that’s usually associated with disease exacerbation and fatalities,” says Silva.

The work was carried out in collaboration with researchers from FMRP-USP, the Oswaldo Cruz Foundation (Fiocruz, affiliated with the Ministry of Health), the Federal University of Alagoas (UFAL) and the University of Brasília (UnB). The group obtained the silver nanoparticles from T. reesei, known for its industrial application in the conversion of cellulose – an important component of plant biomass – into glucose.

In the laboratory, the fungus begins to multiply in a low-oxygen environment, producing a series of reducing enzymes like a biofactory. These molecules transform the silver into spherical nanoparticles. It is worth noting that the enzymes and proteins present in the T. reesei culture medium act as reducing and stabilizing agents, facilitating the formation of silver nanoparticles with controllable sizes and shapes.

“The biological production of silver nanoparticles is a sustainable biotechnological solution because it avoids the use of toxic chemicals. These nanoparticles can be used in nasal spray formulations, disinfectants, antimicrobial coatings and in medical devices to prevent the spread of the virus,” he says.

Silva also points out that the study, conducted with the aim of stopping the spread of SARS-CoV-2, could serve as a basis for treating other viral diseases. “This strategy has proven to be very interesting, generating products for agriculture and the medical and pharmaceutical industries. Originally, my laboratory investigated the use of silver nanoparticles to fight breast tumor cells. With the pandemic, we focused our work on fighting SARS-CoV-2. The application is broad, and there’s already work in animal studies for HIV and the herpes virus, for example,” he says. 

Although silver is expensive, says the researcher, the production of nanoparticles can be scaled up to produce low-cost products. Another important issue is dosage. “Silver is toxic. That’s why we use a very low dosage, ten times less than what’s considered toxic to the body. And after eight weeks, the body is able to eliminate the metal from the body. So the cost-benefit is worth it,” he says. “The next step in this work is to patent a pharmaceutical formulation and start clinical trials.”

About FAPESP

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the state of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration.

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

Biogenic silver nanoparticles produced by Trichoderma reesei inhibit SARS-CoV-2 infection, reduce lung viral load and ameliorate acute pulmonary inflammation by Marcus V.M.V. Amaral, Cláudia B. Carraro, Amanda C.C. Antoniêto, Mariana N. Costa, Thais F.C. Fraga-Silva, Ualter G. Cipriano, Rodrigo P.F. Abuná, Tamara S. Rodrigues, Ronaldo B. Martins, Andreia M. Luzenti, Glaucia R. Caruso, Priscyla D. Marcato, Vania L.D. Bonato, Dario S. Zamboni, Bergman M. Ribeiro, Sônia N. Báo, Joao S. da Silva, Flávio P. Veras, Roberto N. Silva. Current Research in Biotechnology Volume 9, 2025, 100277 DOI: https://doi.org/10.1016/j.crbiot.2025.100277

This paper is open access.

Create silver nanoparticles with goji berries

Leave a reply
Caption: An illustration of the preparation of goji berries for silver nanoparticle synthesis. Credit: Kamran Alam et al.

A January 7, 2025 news item on Nanowerk announces new research into making silver nanoparticles in a more sustainable fashion, Note: Links have been removed,

As the search for sustainability permeates all fields, researchers are turning to a unique organic source for creating antibacterial silver nanoparticles (Ag-NPs) – the humble goji berry.

Goji berries are a ubiquitous superfood known for a multitude of health benefits, including their antibiotic properties. In research published in AIP Advances (“Ecofriendly synthesis of silver nanoparticles using metallic solution-based goji berry extract for their antibacterial properties”), researcher Kamran Alam from Sapienza University of Rome [Italy] along with others from NED University of Engineering and Technology [Pakistan] and King Saud University [Saudi Arabia] found an effective way to harvest silver nanoparticles from these berries.

“Silver nanoparticles are responsible for disrupting the cell membrane structure, which can generate reactive oxygen species used for inhibiting bacterial growth,” explained Alam.

…

A January 7, 2025 American Institute of Physics news release (also on EurekAlert), which originated the news item, delves further into this sustainable technique,

…

Silver nanoparticles can be generated using a number of chemical techniques, but green solutions that use biological sources like fruit or leaf extracts are preferred because they save on energy and are nontoxic, nonhazardous, and biologically compatible with humans.

In this interdisciplinary undertaking, Alam and researchers demonstrated a technique for the synthesis of silver nanoparticles using store-bought goji berries.

“Goji berries are easily and locally available in the botanic garden and are rich in bioactive compounds that have natural reducing and stabilizing agents, eliminating the need for additional capping agents during processing,” Alam said.

Alam and the team created silver nanoparticles by drying, grinding, and then filtering the goji berries to create an extract. Then, they added chemical silver nitrate (AgNO3) and reduced the solution.

Using visualization techniques such as X-ray diffraction, Ultraviolet-Visible (UV-Vis) Spectroscopy, and Fourier Transform Infrared (FT-IR) Spectroscopy, the team confirmed the presence of silver nanoparticles. The nanoparticles were also viewed under a microscope and tested for their antimicrobial activity against Staphylococcus aureus, a gram-positive bacterium that causes staph infections among other diseases.

In the future, Alam plans to study the cellular toxicity and biocompatibility of the nanoparticles synthesized from these berries, which could positively contribute to biomedical research.

“This is a simple and straightforward synthesis method which does not need additional chemicals or complex equipment and can be scaled up for industrial applications,” he said.

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

Ecofriendly synthesis of silver nanoparticles using metallic solution-based goji berry extract for their antibacterial properties by Abdul Rauf Jamali, Waseem Khan, Salahuddin Khan, Ahmed Ahmed Ibrahim, Kamran Alam. AIP Advances 15, 015107 (2025), Volume 15, Issue 1, January 2025 DOI: https://doi.org/10.1063/5.0237276

This paper is open access.

Precise color control in anti-counterfeiting technology with silver nanoparticles trapped in a polymer matrix

Leave a reply

A December 4, 2024 news item on phys.org announces a new anti-counterfeiting technology from South Korea, Note: A link has been removed,

In a significant advancement in the field of anti-counterfeiting technology, Professor Jiseok Lee and his research team in the School of Energy and Chemical Engineering at UNIST [Ulsan National Institute of Science and Technology] have developed a new hidden anti-counterfeiting technology, harnessing the unique properties of silver nanoparticles (AgNPs). The results are published in Advanced Materials.

“The technology we have developed holds significant promise in preventing the counterfeiting of valuable artworks and defense materials, particularly in scenarios where authenticity must be verified against potential piracy,” Professor Lee explained.

…

The original December 4, 2024 Ulsan National Institute of Science and Technology (UNIST) press release by JooHyeon Heo, which originated the news item, provides more details about the work,

Abstract
Silver nanoparticles (AgNPs) are known for their unique plasmonic colors and interaction with light, making them ideal for color printing and data encoding. Traditional methods like electron beam lithography (EBL) and focused ion beam (FIB) milling, however, suffer from low throughput and high costs. In this paper, a scalable and cost-efficient method is introduced for producing multiplexed plasmonic colors by in situ photoreducing AgNPs within microgel architectures with controlled porosity. Utilizing a digital micro-mirror device (DMD)-based flow microlithography system combined with a programmable dithering-mask technique, the high-throughput synthesis of shape or barcoded microparticles is facilitated, along with large-scale, high-resolution images embedded with hidden multiplexed plasmonic colors. This approach allows for a hidden multiplexed plasmonic color code library, significant enhancing the encoding capacity of barcode microparticles from 33 to 303 (a 1000-fold increase). Additionally, quantitative agreement is achieved between chemically encrypted and optically decrypted plasmonic colors using a deep learning classifier. Moreover, the method also supports the production of large scale (>5.6 × 5.6 cm2), high-resolution (>300 dpi) microgel arrays encrypted with multiple plasmonic colors in under 30 min. The multiplexed plasmonic coloration strategy in microgel architectures paves a new way for hidden data storage, secure optical labeling, and anti-counterfeiting technologies.

The portrait of Mookpododo—an ink on-silk painting of grapes featured on the genuine Korean ₩50,000 bill—radiates a bright fluorescent green, an effect achieved through security ink that is visible under ultraviolet (UV) light. This feature remains concealed from the naked eye and is intended for use by professionals in financial institutions and other high-security environments.

[see news item]

The team leveraged the inherent disadvantage of AgNPs, which tend to discolor upon exposure to UV light, to create a controlled color development process. By trapping silver nanoparticles within a polymer matrix, researchers can manipulate particle size and, consequently, the color emitted under UV light. Larger polymer nets yield silver nanoparticles that appear yellow, while smaller nets produce a red hue, allowing for precise control of the resultant colors based on ingredient combinations.

Using these high-molecular structures as pixels, the research team successfully crafted high-resolution color images. Utilizing an automated photo-etching technique, they reduced the fabrication time to one-tenth of traditional methods, producing an image of a parrot larger than a standard business card in just 30 minutes. This digital process allows for flawless color printing, with precise control over saturation and tone.

In addition to images, anti-counterfeiting data can be discreetly embedded in arrangements of polymer structures that resemble red, yellow, and blue barcodes. The color response varies with UV exposure time, allowing for the storage of temporal information within the barcode structure. This innovative approach enables information storage capabilities to increase over 1,000-fold compared to conventional methods, with a potential for unlimited data encoding by arranging barcode particles without additional synthesis.

To enhance the reliability of this technology, the research team developed an artificial intelligence algorithm capable of analyzing barcode authenticity. This AI system boasts a remarkable reliability rate of 98.36%, distinguishing genuine barcodes from counterfeit ones by assessing material composition, UV exposure duration, and barcode integrity.

“The simplicity of the manufacturing process and the reproducibility of colors present a substantial opportunity for the advancement of information encryption systems, particularly in anti-counterfeiting applications,” stated Byungcheon Yoo, the lead author of the study.

The groundbreaking findings from this research were published in the online version of Advanced Materials on November 20, 2024. This research was supported by the National Research Foundation of Korea (NRF).

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

High-Throughput Multiplexed Plasmonic Color Encryption of Microgel Architectures via Programmable Dithering-Mask Flow Microlithography by Byungcheon Yoo, Chaeyeong Ryu, Seunghwan Lee, Sanggyun Jeong, Younghoon You, Dahye Baek, Dowon Kim, Inkyu Jeon, Ki-Seok An, Jongwon Oh, Jiseok Lee. Advanced Materials DOI: https://doi.org/10.1002/adma.202405388 First published: 20 November 2024

This paper is behind a paywall.