Green Silver and Gold Nanoparticles: Methods of Biological Synthesis and Prospects for Biomedical Uses

Niziołek Karina^*
*Correspondence: Niziołek Karina, Department of Nano Biotechnology, Johns Hopkins University, Baltimore, USA, Email:

Introduction

Nanoparticles have garnered significant interest in recent years due to their unique physical, chemical, and biological properties, which distinguish them from their bulk counterparts. Among the various types of nanoparticles, silver (Ag) and gold nanoparticles have become prominent in the fields of biotechnology, medicine, and environmental science. These nanoparticles are especially valuable because of their ease of synthesis, versatility, and wide range of applications, including diagnostics, drug delivery, imaging, and therapy. Notably, the methods used to synthesize these nanoparticles are evolving, with a growing emphasis on sustainable and eco-friendly approaches. Green synthesis, involving biological entities such as plants, fungi, bacteria, and algae, has emerged as a promising alternative to traditional chemical methods, which often involve toxic reagents and harsh conditions. This article explores the biological synthesis of green silver and gold nanoparticles and examines their potential biomedical applications [1].

Description

The synthesis of silver and gold nanoparticles through biological methods, often referred to as green synthesis, has gained attention due to its simplicity, cost-effectiveness, and minimal environmental impact. This method typically involves the reduction of metal ions using plant extracts, microorganisms, or other biological agents as reducing and stabilizing agents. The process is highly advantageous because it avoids the use of hazardous chemicals and energy-intensive procedures, making it a more sustainable approach compared to conventional physical and chemical synthesis methods. Plantbased synthesis of silver and gold nanoparticles has attracted considerable attention due to the wide availability of plant materials and the ease with which they can be processed. Plants, especially those rich in polyphenolic compounds, flavonoids, and other secondary metabolites, serve as effective reducing agents that can reduce metal ions into nanoparticles. Furthermore, plant extracts can also act as stabilizing agents, preventing the agglomeration of nanoparticles and ensuring their stability in solution. Some common plants used for the synthesis of silver and gold nanoparticles include neem (Azadirachta indica), eucalyptus, and aloe vera. These plants are not only abundant but also possess inherent medicinal properties, which can further enhance the therapeutic potential of the synthesized nanoparticles [2,3].

The advantages of biological synthesis methods are manifold. One of the most significant is their environmental sustainability. Traditional chemical methods often involve the use of toxic chemicals, such as stabilizers and solvents, which can pose serious environmental and health risks. In contrast, green synthesis methods rely on naturally occurring compounds that are biodegradable and non-toxic, making them safer for both the environment and human health. Moreover, these biological processes often occur under mild conditions, such as room temperature and neutral pH, which reduces the need for energy-intensive processes, further contributing to their sustainability [4]. Another key benefit of green synthesis is the ease of functionalization. Silver and gold nanoparticles synthesized through biological methods often have a natural coating of biomolecules, such as proteins, lipids, or carbohydrates, which can be exploited for further functionalization. This allows for the tailoring of the surface properties of the nanoparticles, enabling the attachment of various therapeutic agents, targeting ligands, or imaging probes. For example, gold nanoparticles can be functionalized with antibodies for targeted drug delivery, or silver nanoparticles can be modified with antimicrobial peptides for enhanced antimicrobial activity. Such functionalization significantly expands the range of biomedical applications for these nanoparticles. The size, shape, and stability of silver and gold nanoparticles are crucial factors influencing their biological activity and therapeutic potential. Nanoparticles with a small size have a high surface area to volume ratio, which enhances their reactivity and interaction with biological systems. The size and shape of the nanoparticles can be controlled during the synthesis process, with different biological agents influencing these parameters. For example, spherical, rod-like, or triangular nanoparticles exhibit distinct optical and biological properties, making it possible to optimize them for specific applications. Green synthesis methods allow for the tuning of these characteristics in a more controlled manner compared to traditional chemical techniques, which is a key advantage for biomedical applications [5].

Conclusion

Green synthesis of silver and gold nanoparticles offers an environmentally friendly and cost-effective alternative to traditional chemical methods. Through the use of biological agents such as plants, fungi, and bacteria, these nanoparticles can be synthesized with well-controlled size, shape, and surface properties, which are critical for their biomedical applications. The unique properties of silver and gold nanoparticles make them ideal candidates for a wide range of therapeutic and diagnostic applications, including drug delivery, imaging, and infection control. However, further research is needed to fully understand their potential toxicity and to optimize their use in clinical settings. As the field of nanomedicine continues to advance, green-synthesized silver and gold nanoparticles hold great promise for revolutionizing biomedical treatments and improving patient care.

Acknowledgement

None.

Conflict of Interest

None.

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