Biological Synthesis of Metallic Nanoparticles

Biological synthesis of metallic nanoparticles harnesses the reduction potential of living systems or their biomolecules to fabricate metal nanostructures under mild, eco-friendly conditions. Unlike conventional physical and chemical methods that often demand high energy input and toxic reagents, biological approaches exploit bacteria, fungi, algae, plant extracts and purified enzymes to reduce metal ions and stabilise the resulting particles. These routes may proceed intracellularly within microbial cells or extracellularly via secreted proteins, polysaccharides and secondary metabolites, affording precise control over size, shape and surface chemistry. Optimisation of parameters such as pH, temperature, reaction time and biomolecule concentration enables fine-tuning of nanoparticle morphology, from spheres to sheets and core–shell architectures. The inherent biocompatibility and capping by natural molecules facilitate applications across catalysis, environmental remediation, antimicrobial therapies, drug delivery and biosensing. Recent advances in enzyme-mediated synthesis and scale-up protocols underscore the potential for industrial adoption of sustainable nanomanufacturing. Global interest has surged in deploying green nanotechnology to address environmental challenges and develop novel diagnostics and therapeutics, highlighting the interdisciplinary nature and broad societal impact of this field.

Research from Nature Portfolio

Recent studies have explored fungal filtrates to elucidate the interplay between biomolecular fractions and nanoparticle characteristics. One foundational investigation compared extracellular, intracellular and autolysate fractions of thermophilic filamentous fungi, revealing that reducing agents smaller than 3 kDa drove nucleation while larger biomolecules stabilised gold nanoparticles ranging from 6 to 40 nm. This work demonstrated how strain selection and fractionation strategies can tailor size distributions for targeted applications. Another key development involved modulating physicochemical parameters in Trichoderma viride filtrate to generate diverse gold nanoparticle geometries—from nanospheres to nanosheets—by adjusting pH, temperature and reaction time. Subsequent evaluation of catalytic activity in 4-nitrophenol conversion correlated nanoparticle morphology with efficiency, highlighting routes to optimise biodegradation processes through controlled biosynthesis.

Biological Synthesis of Metallic Nanoparticles publication trend

The graph below shows the total number of articles in biological synthesis of metallic nanoparticles across all publications each year (not limited to Nature Index journals).

Technical terms

Biosynthesis: The production of metal nanoparticles through biological organisms or their extracts using biochemical reactions.

Extracellular synthesis: Nanoparticle formation that occurs outside cells via secreted enzymes or metabolites.

Core–shell nanoparticle: A nanostructure comprising a metal core enclosed by a different metal or material shell to combine distinct properties.

Capping agent: A biomolecule that attaches to nanoparticle surfaces to prevent aggregation and control growth.

Sporicidal activity: The ability of a substance to inactivate or destroy bacterial endospores.

Enantioselective catalysis: A catalytic process that preferentially forms one enantiomer of a chiral product.

References

1. Controlled Biocatalytic Synthesis of a Metal Nanoparticle‐Enzyme Hybrid: Demonstration for Catalytic H2‐driven NADH Recycling. Angewandte Chemie International Edition (2024).
2. Fungal biosynthesis of gold nanoparticles with sporicidal activity against bacterial endospores. Green Chemistry Letters and Reviews (2024).
3. Green synthesis of gold nanoparticles by thermophilic filamentous fungi. Scientific Reports (2018).
4. Physico-Chemical Condition Optimization during Biosynthesis lead to development of Improved and Catalytically Efficient Gold Nano Particles. Scientific Reports (2016).
5. Gold Nanoparticles: Biosynthesis and Potential of Biomedical Application. Journal of Functional Biomaterials (2021).