Researchers have developed an eco-friendly method to produce silver nanoparticles from the roots of Martynia annua, showing strong antioxidant and anti-diabetic potential while avoiding the toxic by-products of conventional synthesis.
Silver nanoparticles are particularly popular in research because of their high surface area-to-volume ratio, which boosts their reactivity and biological performance. However, producing these tiny particles is energy-intensive, uses toxic reagents, and generates hazardous waste.
Researchers are turning to plants to find a less environmentally compromising route to synthesis. Known as photosynthesis, scientists can harness the natural phytochemicals in plants to reduce silver ions (Ag+) to elemental silver (Ag0) and stabilize the resulting particles, preventing aggregation. The key compounds involved are terpenoids, flavonoids, saponins, and phenolics, among others.
The new study, published in Nano TransMed, focuses on Martynia annua, a plant with a rich phytochemical profile, particularly its roots, as the biological source for nanoparticle production.
The researchers first prepared an aqueous extract of Martynia annua roots, filtering the liquid carefully to retain the phytochemicals required for nanoparticle formation. When combined with a silver nitrate (AgNO3) solution under controlled conditions, the extract showed a visible change in color from pale yellow to reddish-brown, signalling the onset of surface plasmon resonance, a distinctive optical property of metal nanoparticles that confirms their synthesis.
The nanoparticles were characterized using several complementary techniques: UV/Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and dynamic light scattering (DLS).
UV/Vis spectroscopy revealed a peak at around 420 nm, a wavelength typical of silver nanoparticles. This provided further confirmation of the formation of particles exhibiting surface plasmon resonance.
FTIR identified functional groups on the particle surfaces, such as hydroxyl and carbonyl moieties, indicating the involvement of plant-derived compounds in capping and stabilization.
SEM images showed that the nanoparticles were predominantly polygonal or irregular in shape. EDX confirmed the elemental composition of the nanoparticles, with a majority of silver present at 58.08 %, and trace amounts of other elements.
DLS measured the hydrodynamic diameter of the particles at roughly 64 nm, with a polydispersity index of 0.385, suggesting a relatively uniform size distribution suitable for biomedical applications. Zeta potential analysis indicated a surface charge of -21.6 mV, reflecting moderate colloidal stability and a reduced tendency for the nanoparticles to clump together in suspension.
Phytochemical analysis of the root extract confirmed a strong presence of terpenoids, which are believed to facilitate both the reduction of silver ions and the long-term stability of the nanoparticles.
Strong Bioactivity
The team also assessed the biological properties of the Martynia annua-derived silver nanoparticles to assess their therapeutic potential.
Antioxidant assays of the particles demonstrated strong free radical scavenging ability in the DPPH test and substantial ferric reducing antioxidant power, important in counteracting oxidative stress. In diabetes, where oxidative stress plays a significant role in the onset and progression of the illness, this is particularly promising.
The nanoparticles inhibited α-amylase in enzymatic studies, an enzyme responsible for breaking down complex carbohydrates into simple sugars. By limiting α-amylase activity, the nanoparticles may help reduce post-meal spikes in blood glucose levels. Further, in cell-based experiments, they were found to enhance glucose uptake, indicating potential for improving glucose homeostasis in diabetic conditions.
A Sustainable Path Forward
Taken together, these results demonstrate that the green synthesis of silver nanoparticles from Martynia annua roots is both feasible and effective, producing stable, well-defined particles with strong antioxidant properties. The combination of favourable physicochemical attributes, such as appropriate size, shape, surface charge, and stability, with measurable biological benefits suggests these plant-derived nanoparticles could contribute to new therapeutic strategies.
With growing demand for environmentally responsible nanotechnology, such plant-mediated methods could help to strike a balance between sustainable manufacturing and high-performance biomedical materials.
Journal Reference
Abbigeri M.B., et al. (2025). Green synthesis of silver nanoparticles from Martynia annua: characterization and bioactivity. Nano TransMed, 4, 100070. DOI: 10.1016/j.ntm.2025.100070, https://www.sciencedirect.com/science/article/pii/S2790676025000019
News
Nanomedicine in 2026: Experts Predict the Year Ahead
Progress in nanomedicine is almost as fast as the science is small. Over the last year, we've seen an abundance of headlines covering medical R&D at the nanoscale: polymer-coated nanoparticles targeting ovarian cancer, Albumin recruiting nanoparticles for [...]
Lipid nanoparticles could unlock access for millions of autoimmune patients
Capstan Therapeutics scientists demonstrate that lipid nanoparticles can engineer CAR T cells within the body without laboratory cell manufacturing and ex vivo expansion. The method using targeted lipid nanoparticles (tLNPs) is designed to deliver [...]
The Brain’s Strange Way of Computing Could Explain Consciousness
Consciousness may emerge not from code, but from the way living brains physically compute. Discussions about consciousness often stall between two deeply rooted viewpoints. One is computational functionalism, which holds that cognition can be [...]
First breathing ‘lung-on-chip’ developed using genetically identical cells
Researchers at the Francis Crick Institute and AlveoliX have developed the first human lung-on-chip model using stem cells taken from only one person. These chips simulate breathing motions and lung disease in an individual, [...]
Cell Membranes May Act Like Tiny Power Generators
Living cells may generate electricity through the natural motion of their membranes. These fast electrical signals could play a role in how cells communicate and sense their surroundings. Scientists have proposed a new theoretical [...]
This Viral RNA Structure Could Lead to a Universal Antiviral Drug
Researchers identify a shared RNA-protein interaction that could lead to broad-spectrum antiviral treatments for enteroviruses. A new study from the University of Maryland, Baltimore County (UMBC), published in Nature Communications, explains how enteroviruses begin reproducing [...]
New study suggests a way to rejuvenate the immune system
Stimulating the liver to produce some of the signals of the thymus can reverse age-related declines in T-cell populations and enhance response to vaccination. As people age, their immune system function declines. T cell [...]
Nerve Damage Can Disrupt Immunity Across the Entire Body
A single nerve injury can quietly reshape the immune system across the entire body. Preclinical research from McGill University suggests that nerve injuries may lead to long-lasting changes in the immune system, and these [...]
Fake Science Is Growing Faster Than Legitimate Research, New Study Warns
New research reveals organized networks linking paper mills, intermediaries, and compromised academic journals Organized scientific fraud is becoming increasingly common, ranging from fabricated research to the buying and selling of authorship and citations, according [...]
Scientists Unlock a New Way to Hear the Brain’s Hidden Language
Scientists can finally hear the brain’s quietest messages—unlocking the hidden code behind how neurons think, decide, and remember. Scientists have created a new protein that can capture the incoming chemical signals received by brain [...]
Does being infected or vaccinated first influence COVID-19 immunity?
A new study analyzing the immune response to COVID-19 in a Catalan cohort of health workers sheds light on an important question: does it matter whether a person was first infected or first vaccinated? [...]
We May Never Know if AI Is Conscious, Says Cambridge Philosopher
As claims about conscious AI grow louder, a Cambridge philosopher argues that we lack the evidence to know whether machines can truly be conscious, let alone morally significant. A philosopher at the University of [...]
AI Helped Scientists Stop a Virus With One Tiny Change
Using AI, researchers identified one tiny molecular interaction that viruses need to infect cells. Disrupting it stopped the virus before infection could begin. Washington State University scientists have uncovered a method to interfere with a key [...]
Deadly Hospital Fungus May Finally Have a Weakness
A deadly, drug-resistant hospital fungus may finally have a weakness—and scientists think they’ve found it. Researchers have identified a genetic process that could open the door to new treatments for a dangerous fungal infection [...]
Fever-Proof Bird Flu Variant Could Fuel the Next Pandemic
Bird flu viruses present a significant risk to humans because they can continue replicating at temperatures higher than a typical fever. Fever is one of the body’s main tools for slowing or stopping viral [...]
What could the future of nanoscience look like?
Society has a lot to thank for nanoscience. From improved health monitoring to reducing the size of electronics, scientists’ ability to delve deeper and better understand chemistry at the nanoscale has opened up numerous [...]
