Green Adeptness in the Synthesis and Stabilization of Copper Nanoparticles: Catalytic, Antibacterial, Cytotoxicity, and Antioxidant Activities

Abstract

Copper nanoparticles (CuNPs) are of great interest due to their extraordinary properties such as high surface-to-volume ratio, high yield strength, ductility, hardness, flexibility, and rigidity. CuNPs show catalytic, antibacterial, antioxidant, and antifungal activities along with cytotoxicity and anticancer properties in many different applications. Many physical and chemical methods have been used to synthesize nanoparticles including laser ablation, microwave-assisted process, sol-gel, co-precipitation, pulsed wire discharge, vacuum vapor deposition, high-energy irradiation, lithography, mechanical milling, photochemical reduction, electrochemistry, electrospray synthesis, hydrothermal reaction, microemulsion, and chemical reduction. Phytosynthesis of nanoparticles has been suggested as a valuable alternative to physical and chemical methods due to low cytotoxicity, economic prospects, environment-friendly, enhanced biocompatibility, and high antioxidant and antimicrobial activities. The review explains characterization techniques, their main role, limitations, and sensitivity used in the preparation of CuNPs. An overview of techniques used in the synthesis of CuNPs, synthesis procedure, reaction parameters which affect the properties of synthesized CuNPs, and a screening analysis which is used to identify phytochemicals in different plants is presented from the recent published literature which has been reviewed and summarized. Hypothetical mechanisms of reduction of the copper ion by quercetin, stabilization of copper nanoparticles by santin, antimicrobial activity, and reduction of 4-nitrophenol with diagrammatic illustrations are given. The main purpose of this review was to summarize the data of plants used for the synthesis of CuNPs and open a new pathway for researchers to investigate those plants which have not been used in the past. Graphical abstractProposed Mechanism for Antibacterial activity of copper nanoparticles.

The Effect of the Antioxidant Activity of Plant Extracts on the Properties of Gold Nanoparticles

“…Additionally, AuNPs obtained by green technologies are used as catalysts in the decomposition of 4-nitrophenol [24,25], as electrode modifiers in the determination of chloramphenicol in milk, honey and eye drops [26], carbendazim in soil [27], lead ions in paints and river waters [28], ecotoxicant hydrazine [29], uric acid in milk and blood serum [30].Currently, green methods for AuNPs synthesis are being developed using various bio-objects with high reducing ability: bacteria, viruses, fungi and yeast, plants and algae [31][32][33]. A distinctive feature of the nanoparticle's synthesis with the use of plants (the so-called phytosynthesis) is a higher rate of nanoparticle formation compared to the synthesis rate with the use of microorganisms [34] and the fact that additional reagents are not required [35][36][37][38][39]. Leaf extracts contain a wide range of biomolecules and metabolites, such as terpenoids [act as reducing agents and stabilizers of nanosuspensions in the process of phytosynthesis.…”

“…Currently, green methods for AuNPs synthesis are being developed using various bio-objects with high reducing ability: bacteria, viruses, fungi and yeast, plants and algae [31][32][33]. A distinctive feature of the nanoparticle's synthesis with the use of plants (the so-called phytosynthesis) is a higher rate of nanoparticle formation compared to the synthesis rate with the use of microorganisms [34] and the fact that additional reagents are not required [35][36][37][38][39]. Leaf extracts contain a wide range of biomolecules and metabolites, such as terpenoids [act as reducing agents and stabilizers of nanosuspensions in the process of phytosynthesis.…”

Antimicrobial activity of copper‐humate‐cellulose sheets

“…Furthermore, the sulfhydryl groups of the bacterial membrane also attract copper ions . Cell membrane‐bound copper ions has been shown to damage the bacterial cell membrane . Moreover, copper ions penetrating into bacterial cells through the damaged membrane also damage bacterial enzymes .…”

“…90 Cell membrane-bound copper ions has been shown to damage the bacterial cell membrane. 91 Moreover, copper ions penetrating into bacterial cells through the damaged membrane also damage bacterial enzymes. 92 The inhibition of the growth of fungi and mould is also based on a similar mechanism.…”

Nanoparticles as New Therapeutic Agents against Candida albicans

“…Diverse synthesis methods have been proved to create CuONPs including chemical [85], electrochemical [86], and green synthesis [87].…”