The ever-growing range of possible applications of nanoparticles requires their mass production. However, there are problems resulting from the prevalent methods of nanoparticle production; physico-chemical routes of nanoparticle synthesis are not very environmentally friendly nor cost-effective. Due to this, the scientific community started exploring new methods of nanoparticle assembly with the aid of biological agents. In this study, ethanolic Vitis vinifera cane extract combined with silver nitrate was used to produce silver nanoparticles. These were subsequently characterized using UV-visible (UV-Vis) spectrometry, transmission electron microscopy, and dynamic light-scattering analysis. The antimicrobial activity of produced nanoparticles was tested against the planktonic cells of five strains of Gram-negative bacterium Pseudomonas aeruginosa (PAO1, ATCC 10145, ATCC 15442, DBM 3081, and DBM 3777). After that, bactericidal activity was assessed using solid medium cultivation. In the end, nanoparticles’ inhibitory effect on adhering cells was analyzed by measuring changes in metabolic activity (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay-MTT). Our results confirmed that ethanolic Vitis vinifera cane extract is capable of mediating silver nanoparticle production; synthesis was conducted using 10% of extract and 1 mM of silver nitrate. The silver nanoparticles’ Z-average was 68.2 d nm, and their zeta potential was –30.4 mV. These silver nanoparticles effectively inhibited planktonic cells of all P. aeruginosa strains in concentrations less than 5% v/v and inhibited biofilm formation in concentrations less than 6% v/v. Moreover, minimum bactericidal concentration was observed to be in the range of 10–16% v/v. According to the results in this study, the use of wine agriculture waste is an ecological and economical method for the production of silver nanoparticles exhibiting significant antimicrobial properties.

The utilization of waste materials for the synthesis of nanoparticles has gained significant attention due to its potential for waste valorization and contribution to circular economy. In this study, bimetallic nanoparticles were produced using extracts derived from Cannabis sativa and Vitis vinifera waste, focusing on their green synthesis and antimicrobial activity against Gram-negative bacteria, specifically several strains of Pseudomonas aeruginosa. The Vitis vinifera canes and post-extraction waste from Cannabis sativa were processed using an ethanol extraction method. The extract was then mixed with silver nitrate and tetrachloroauric acid solution at different reagent ratios to optimize the synthesis process. The resulting bimetallic nanoparticles (AgAuNPs) were characterized using UV-vis spectrophotometry, transmission electron microscopy, atomic absorption spectrometry, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The antimicrobial activity of the biosynthesized AgAuNPs was evaluated against various strains of Pseudomonas aeruginosa. The minimal inhibitory concentration (MIC) was determined using a microcultivation device, and the minimal bactericidal concentration (MBC) was determined through subsequent solid medium cultivation. Additionally, the minimal biofilm inhibitory concentration (MBIC) was assessed using a polystyrene microtiter plate as biofilm carrier and measured through an assay determining the metabolic activity of biofilm cells. The results demonstrated successful synthesis of bimetallic nanoparticles using the extracts from Cannabis sativa and Vitis vinifera waste. The AgAuNPs exhibited significant antimicrobial activity against the tested Pseudomonas aeruginosa strains, inhibiting their growth and biofilm formation. These findings highlight the potential of waste valorization and circular economy in nanoparticle production and their application as effective antimicrobial agents. This study contributes to the growing field of sustainable nanotechnology and provides insights into the utilization of plant waste extracts for the synthesis of bimetallic nanoparticles with antimicrobial properties. The findings support the development of eco-friendly and cost-effective approaches for nanoparticle production while addressing the challenges of waste management and combating microbial infections.