Plant-Extract-Mediated Synthesis of Metal Nanoparticles

Abstract

Metal nanoparticles (MNPs) have been widely used in several fields including catalysis, bioengineering, photoelectricity, antibacterial, anticancer, and medical imaging due to their unique physical and chemical properties. In the traditional synthesis method of MNPs, toxic chemicals are generally used as reducing agents and stabilizing agents, which is fussy to operate and extremely environment unfriendly. Based on this, the development of an environment-friendly synthesis method of MNPs has recently attracted great attention. The use of plant extracts as reductants and stabilizers to synthesize MNPs has the advantages of low cost, environmental friendliness, sustainability, and ease of operation. Besides, the as-synthesized MNPs are nontoxic, more stable, and more uniform in size than the counterparts prepared by the traditional method. Thus, green preparation methods have become a research hotspot in the field of MNPs synthesis. In this review, recent advances in green synthesis of MNPs using plant extracts as reductants and stabilizers have been systematically summarized. In addition, the insights into the potential applications and future development for MNPs prepared by using plant extracts have been provided.

Biomimetic Metallic Nanostructures for Biomedical Applications, Catalysis, and Beyond

“…157,158 These biomolecules can act as a surfactant, stabilizer, and/or reducing agents in the synthesis of biometal NPs (Figure 1c). 32,159 In general, three steps are involved in the plant-mediated synthesis of metal NPs: activation, growth, and stabilization. In the activation phase, phytomolecules convert metal cations into metal atoms through the redox reaction and the metal atoms commence the nucleation.…”

“…They produce several primary and secondary metabolites, including amino acids, sugars, lipids, proteins carbohydrates, vitamins, water-soluble polyphenols (e.g., flavonoids, phenolic acids, tannins, anthocyanins, stilbenes, and lignans), alkaloids, quinines, terpenoids, and saponins. These phytochemicals act as natural pesticides in protecting plants against external biotic and abiotic aggressions, like fungi, bacteria, insects, herbivores, and UV radiation. , These biomolecules can act as a surfactant, stabilizer, and/or reducing agents in the synthesis of biometal NPs (Figure c). , In general, three steps are involved in the plant-mediated synthesis of metal NPs: activation, growth, and stabilization. In the activation phase, phytomolecules convert metal cations into metal atoms through the redox reaction and the metal atoms commence the nucleation.…”

“…The size and shape of the as-synthesized metal NPs will be determined by this step; if this phase continues for a long period, the metal NPs can aggregate and become irregularly shaped. Finally, in the stabilization phase, the phytomolecules enclose the metallic nanoparticles, which prevents their overgrowth and results in the energetically stable forms. , So, scientists have been encouraged to use plants as a facile, cost-saving, and effective means of biosynthesizing metal NPs. However, the amounts and types of phytochemical compounds in plants depend on the seasonal and climatic conditions, which affect the final properties and reproducibility of the plant-based synthesized metal NPs.…”

Smart and Multi-Functional Magnetic Nanoparticles for Cancer Treatment Applications: Clinical Challenges and Future Prospects

“…The plant-mediated pathway is based on co-precipitation via the reduction of iron ions in the presence of a plant extract acting as a reductant/capping agent. Although green co-precipitation fabricates biocompatible particles with diverse shapes (elliptical rode, cube-spherical), its major disadvantage is poor size control, low crystallinity, and poly disperse particles [ 46 , 47 , 48 ].…”

Biogenic Synthesis of Silver Nanoparticles Using Terminalia chebula Retz. Leaf Extract and Evaluation of Biological Activities

“…The different bioactive constituents present in the living system help in the direct reduction of silver ions and also act as a good natural capping agent. Mostly the bio-constituents present in the biological source like phenols, flavonoids, terpenoids, quinines tannins, etc; are playing a vital role in those activities [13][14].…”