How Mushrooms Are Brewing Next-Gen Silver Nanoparticles
In the quest for sustainable technology, scientists are turning to an unlikely ally: mushrooms. These fungal powerhouses are now at the forefront of green nanotechnology, revolutionizing how we synthesize silver nanoparticles (AgNPs)—microscopic structures with colossal potential.
Unlike traditional chemical methods that rely on toxic solvents, mushrooms offer an eco-friendly alternative, transforming silver ions into potent antimicrobial and antioxidant agents using only their natural biochemistry 1 6 .
Mushrooms excel in nanoparticle synthesis due to their rich biochemical arsenal. When exposed to silver ions (Ag⁺), compounds like phenols, proteins, and enzymes (e.g., NADH-dependent reductases) in mushroom extracts act as reducing and capping agents.
These molecules donate electrons to convert Ag⁺ into metallic silver (Ag⁰), which self-assembles into nanoparticles stabilized by the fungal biomolecules 6 7 .
Critical parameters fine-tune AgNP properties:
8-10 (alkaline)
60-80°C
60-90 mins
From Mushroom Extract to Antimicrobial Powerhouse
A landmark study by Abdalrahman & Suliaman (2024) illustrates this process using four mushroom species: Chlorophyllum agaricoides, Ganoderma sp., Lentinus tigrinus, and Coriolopsis trogii 1 :
| Technique | Observation | Significance |
|---|---|---|
| UV-Vis Spectroscopy | Peak absorbance at 424-426 nm | Surface plasmon resonance confirms AgNP formation |
| XRD | Crystallite sizes: 25.31-31.42 nm | Cubic crystal structure; high purity |
| FTIR | Peaks at 1635 cm⁻¹ (amide bonds) | Proteins/polysaccharides cap AgNPs |
| SEM/AFM | Spherical particles, 20-100 nm diameter | Uniform morphology enhances bioactivity |
| Pathogen | Inhibition Zone (mm) | Most Effective Source |
|---|---|---|
| Escherichia coli | 18-22 | Ganoderma sp. |
| Staphylococcus aureus | 20-25 | Lentinus tigrinus |
| Candida albicans | 15-18 | Coriolopsis trogii |
AgNPs attack pathogens through physical and biochemical pathways 3 4 :
Nanoparticles adhere to cell walls, generating pores that cause leakage.
Ag⁺ ions release reactive oxygen species (ROS), damaging DNA/proteins.
Despite being "oxidants" against microbes, AgNPs exhibit radical-scavenging behavior in biological systems. Phenolic compounds (e.g., hispidin in Inonotus hispidus) on AgNP surfaces donate electrons to neutralize free radicals like DPPH—crucial for reducing oxidative stress in human cells 2 5 .
| Reagent/Equipment | Function |
|---|---|
| Mushroom extract | Reducing/capping agent |
| Silver nitrate (AgNO₃) | Silver ion source |
| Centrifuge | Purification of AgNPs |
| UV-Vis Spectrophotometer | Confirmation of AgNP formation |
| FTIR Spectrometer | Identification of capping biomolecules |
AgNPs from Ganoderma sessiliforme embedded in packaging inhibit Listeria and E. coli, extending shelf life 4 .
Nano-fungicides (e.g., Azadirachta-stabilized AgNPs) suppress crop pathogens like Rhizoctonia solani at concentrations as low as 33 ppm 5 .
Mushroom-mediated AgNP synthesis merges ancient biological wisdom with cutting-edge science. By harnessing fungal biochemistry, researchers are developing safer, more effective alternatives to conventional antimicrobials and antioxidants.
Key Takeaway: The future of nanotechnology isn't just in labs—it's in forests, fields, and the extraordinary metabolism of mushrooms.