Nanotechnology exploration has recently sparked significant interest within the domain of material sciences. It stands out as one of the latest breakthroughs imbued with novelty and quintessentially addresses the emerging challenges our world faces. In the pharmaceutical and biomedical industries, nanoparticles exhibit a diverse range of applications, including gene and drug delivery systems, water disinfection, electronics, biosensors, as well as serving as agents for anticancer, antibacterial, antifungal, and antiprotozoal purposes (Lee and Jun, 2019; Rai et al., 2021; War et al., 2022). In recent years, there has been significant research interest in the biosynthesis and characterization of nanoparticles. This interest is primarily driven by their large surface area, which imparts unique properties and potential applications distinct from their bulk counterparts (Shnoudeh et al., 2019; Sajid and Płotka-Wasylka, 2020). Up to now, nanoparticles have been synthesized using a variety of chemical and physical techniques. However, biosynthesis approach utilizing biological systems such as plants, fungi, yeast, and bacteria has been explored and adopted globally for nanoparticle biosynthesis due to its environmentally friendly, reproducible, non-toxic, and cost-effective nature (Gudikandula et al., 2017; Hano and Abbasi, 2021).The biosynthesis approach offers many advantages over chemical synthesis (Duan et al., 2015; Roy et al., 2019; Murali et al., 2023). Since biological systems operate as natural reducing, stabilizing, and capping agents, thereby avoiding many processes for the synthesis of nanoparticles, which not only decreases the cost and consumption of chemicals, but also eliminates agglomeration and oxidation of synthesized nanoparticles (Sidhu et al., 2022). Metallic nanoparticles, especially silver nanoparticles (AgNPs) produced through biological sources, have undergone intensive investigation as a potential alternative therapy for a wide range of infections and illnesses (Bhuyan et al., 2017; Al-Ansari et al., 2020; Murali et al., 2021; Nandi et al., 2023).

Silver is widely known to combat certain microorganisms by modifying their cell membrane structure and function (Dakal et al., 2016; Mikhailova, 2020; Das and Dutta, 2021). Silver is employed as a disinfectant in water purification systems due to its ability to destroy bacteria at low concentrations (less than 1–10 m) (Liu et al., 1994; Deshmukh et al., 2019; Bhardwaj et al., 2021; Das and Dutta, 2022). However, silver can be hazardous to animals, freshwater, and marine organisms at greater quantities (Tortella et al., 2020). Interestingly, micromolar quantities of silver are not toxic to humans (Vrček et al., 2016). Therefore, silver has been widely used in the production of various biological and medicinal products. Recent studies revealed that the toxicity of Ag-NPs measured in freshwater depends on the test species (Blinova et al., 2013). For example, Ag-NPs are reported to be toxic for crustaceans at very low concentration (EC₅₀ < 0.1 mg L⁻¹), followed by algae (EC₅₀ = 0.23 mg L⁻¹), but the toxicity to fish is relatively low (EC₅₀ = 7.1 mg L⁻¹, Kahru and Dubourguier, 2010; Asghari et al., 2012). It has been observed that effects of AgNP on the T84 epithelial cells were size- and dose-dependent, with the 10 nm AgNP causing the most significant changes. Changes in permeability of the epithelial cell monolayer, as measured by transepithelial electrical resistance, after exposure to 10 nm AgNP were most dramatic at the highest dose (100 μg/mL), but also observed at the lower dose (20 μg/mL) (Williams et al., 2016).

Presently, AgNPs are widely utilized across a broad spectrum of applications, ranging from electronic devices to biological tools (Garg et al., 2020; Tufail and Liaqat, 2021; Naganthran et al., 2022). This is likely due to the stability of the particles, which holds significant importance for various applications, particularly in medicine. Additionally, it is crucial that nanoparticles do not agglomerate during their formation, to achieve enhanced stability, maximal yield, and controlled size aggregation of particles, optimization of the various parameters employed in plant-mediated nanoparticle biosynthesis is essential (Ebrahiminezhad et al., 2018; Ahmad et al., 2024). Recent reports have demonstrated the broad-spectrum antibacterial activity of AgNPs against both Gram-positive and Gram-negative bacteria, including multidrug-resistant strains (Liao et al., 2019; Ansari et al., 2021; Yassin et al., 2022). It is significant that AgNPs exhibit multiple modes of inhibitory action against microorganisms, as opposed to the single specific action of antibiotics (Vazquez-Muñoz et al., 2019). Interestingly, AgNPs demonstrate efficacy against various fungi, including Candida spp., dermatophytes, and certain phytopathogenic fungi such as Bipolaris sorokiniana and Magnaporthe grisea (Rajeshkumar, 2019; Mansoor et al., 2021). Conversely, various phytopathogenic fungi remain unexplored, despite their role in causing severe diseases in crucial crop plants, consequently diminishing agricultural yield. Therefore, the present study aimed to address the following questions: (a) to study the preparation and characterization of silver nanoparticles. (b) To study the efficacy of various concentrations of biosynthesized silver nanoparticles against fungal pathogens.

Plant pathogens such as bacteria and fungi are controlled by different traditional management strategies. However, some of these management measures, such as the use of pesticides, have negative environmental consequences due to their limits. As a result, alternative ways are used that are more environmentally friendly and have fewer negative consequences on human health and the environment. As a result, the antimycotic activity of various AgNPs was tested against fungal pathogens in this work. These AgNPs were prepared by simple technique and used at different concentrations against pathogenic fungi. AgNPs were biosynthesized using Rhizoctonia solani and Cladosporium cladosporioides. After preparation of these AgNPs they were processed to prepare different concentrations. These different concentrations of AgNPs were screened for their antifungal activity against fungal pathogens.

Nano-biotechnology is quickly developing as an important field of modern research, generating the most promising applications in medicine and agriculture in the present climate change scenario (Mariyam et al., 2023). The application of nano-biotechnology in agriculture will help in addressing and solving inherent imperfections and other complex problems in farm production with low input but with an efficient role due to their unique size (Dimkpa and Bindraban, 2017; Usman et al., 2020). Biosynthesis of AgNPs using green approach provide ecofriendly, clean and effective way out for the biosynthesis of nanoparticles. These nanoparticles differ in shape, size, chemical composition and other properties (Raj et al., 2021).

During the present study, Rhizoctonia solani and Cladosporium cladosporioides were used to biosynthesize AgNPs, which was proved by the appearance of brown color due to reduction of silver salt into AgNPs by fungal culture filtrates along with the appearance of strong plasmon absorbance bands at 420–450 nm and strong resonance peaks at 440 nm, thus confirming the biosynthesis of AgNPs as has been reported by Khan et al. (2018) and Paul et al. (2023). Many researchers have reported that microorganisms, plant extracts, and fungi can be used to biosynthesize nanoparticles through biological pathways (Koul et al., 2021). Many fungi like Fusarium oxysporum, Aspergillus fumigatus, Aspergillus niger, Fusarium semitectum, Penicillium brevicompactum, and Cladosporium cladosporioides have been reported to be competent enough to extracellularly biosynthesized AgNPs (Rajeshkumar and Sivapriya, 2020; Adebayo et al., 2021) respectively. Our results are in conformity with Verma et al. (2010) and Parveen et al. (2018), who also reported similar results for biosynthesis AgNPs and iron oxide nanoparticles from fungi, respectively. Fungi have many advantages for the production and biosynthesis of nanoparticles in comparison to other types of microorganisms and phyto extracts. This is because the mycelial mesh of fungi is easy to handle and withstands high flow pressure, agitation and many other conditions in bioreactors and other chambers. Scanning electron microscopy revealed that biosynthesized AgNPs were irregular and spherical in aggregate form, with a size ranging from 80 to 100 nm. Similar patterns of biosynthesized AgNPs were observed by Kathiresan et al. (2009) and Jain et al. (2011). Our findings are in accordance with the work of Al-Zubaidi et al. (2019) and Talie et al. (2020) who also used different microfungi and macrofungi for biosynthesis of AgNPs. It seems that the pattern aggregation and formation of mycosynthesized silver nanoparticles take place due to the enzymatic reduction of silver metal ions (Rajput et al., 2016). The results from the present study with regard to the bioactivity of biosynthesized AgNPs against phytopathogenic fungi revealed that at different concentrations, biosynthesized AgNPs caused a significant reduction in the fungal mycelial growth in terms of zone of inhibition against all the test fungal pathogens such as Rhizoctonia solani and Cladosporium cladosporioide indicating their strong antimycotic activity. Similar work was carried out by Abd-Elsalam et al. (2019), Ingle et al. (2020), Padhi and Behera (2021). Sulaiman et al. (2015) and reported antimycotic activity of bi-synthesized AgNPs against fungi, namely Aspergillus niger, Penicillium chrysogenum, Fusarium culmorum, and Alternaria alternata. Talie et al. (2020) also reported the potent antifungal activity of biosynthesized AgNPs using Helvella leucopus against Aspergillus niger, Penicillium chrysogenum, Alternaria alternata which is in conformity with our work. The results emphasize that these biosynthesized AgNPs will work best as nano-biopesticides, as has been reported by Paramo et al. (2020) and can be incorporated into the integrated disease management module. Antimycotic activity of AgNPs against different species of phytopathogenic fungi of some cereals was reported by Al-Askar et al. (2013) and Candida species by Ishida et al. (2013). Since phytopathogenic fungi are toxic due to the production of mycotoxins which can be easily adsorbed by nanoparticles and impart protection against disease as has been reported by Horky et al. (2018).

This study focused on the biosynthesis of AgNPs from aqueous extract of the fungi, Rhizoctonia solani and Cladosporium cladosporioides. The biogenic method provides natural agents for reduction, capping and stabilization of AgNPs, which makes the synthesis approach much more cost-effective, non-toxic, reproducible and environmentally friendly, implying that fungi could be a good source of silver nanoparticles. Biosynthesized silver nanoparticles from Rhizoctonia solani and Cladosporium cladosporioides were crystallite in nature, with an average particle size of 10.100 nm. The study revealed strong antifungal properties of these synthesized AgNPs. A significant zone of mycelial growth inhibition by AgNPs was observed against all the test microorganisms. These silver nanoparticles could be of tremendous use in pharmaceutical industries for various biomedical purposes, as well as in food processing industries for food packaging to reduce contamination and enhance long-term storage and preservation of foods. Metal based nanoparticles such as silver nanoparticles may prove to be very beneficial in the agricultural sector, such as their use as nanopesticides. However, proper investigation into their mechanism of action and evaluating the impact on human health and the environment is required.

The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.

MM: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Software, Visualization, Writing – original draft, Writing – review & editing. AW: Data curation, Project administration, Resources, Validation, Writing – review & editing. MB: Data curation, Investigation, Project administration, Writing – review & editing. SS: Funding acquisition, Writing – review & editing. SAMA: Writing – review & editing. SAA: Writing – review & editing.