Fungal infections cause severe crop losses (15–60%) despite the use of antifungal agents, a problem exacerbated by climate change, population growth, and resistance. Regulatory restrictions on compounds like tebuconazole highlight the need for sustainable alternatives. This study evaluates the antifungal efficacy of chitosan nanoparticles loaded with Sideritis serrata extract (NPCH-SID) as an eco-friendly solution. The extract was obtained by freeze-drying and ethanol extraction, while NPCH-SID was synthesized via ionic gelation, achieving optimal size and encapsulation efficiency. In vitro assays revealed broad antifungal activity, with up to 156,140-fold improvement against Aspergillus brasiliensis compared to the free extract. Phytotoxicity tests on wheat seeds showed ~95% germination and enhanced root and shoot growth, confirming the safety and growth-promoting effect of this method. These findings position NPCH-SID as a promising tool for sustainable agriculture. Future work will assess its performance against additional pathogens under greenhouse and field conditions.

Biogenic silver nanoparticles (AgNPs) were synthesized via a green chemistry strategy using wheat extract and subsequently functionalized with a carboxymethyl chitosan–cinnamaldehyde (CMC=CIN) conjugate through covalent imine bonding. The resulting nanohybrid (AgNP–CMC=CIN) was extensively characterized to confirm successful biofunctionalization: UV–Vis spectroscopy revealed characteristic cinnamaldehyde absorption peaks; ATR-FTIR spectra confirmed polymer–terpene bonding; and TEM analysis evidenced uniform nanoparticle morphology. Dynamic light scattering (DLS) measurements indicated an increase in hydrodynamic size upon coating (from 59.46 ± 12.63 nm to 110.17 ± 4.74 nm), while maintaining low polydispersity (PDI: 0.29 to 0.27) and stable surface charge (zeta potential ~ −30 mV), suggesting colloidal stability and homogeneous polymer encapsulation. Antifungal activity was evaluated against Fusarium oxysporum, Penicillium citrinum, Aspergillus niger, and Aspergillus brasiliensis. The minimum inhibitory concentration (MIC) against F. oxysporum was significantly reduced to 83 μg/mL with AgNP–CMC=CIN, compared to 708 μg/mL for uncoated AgNPs, and was comparable to the reference fungicide tebuconazole (52 μg/mL). Seed priming with AgNP–CMC=CIN led to improved germination (85%) and markedly reduced fungal colonization, while maintaining a favorable phytotoxicity profile. These findings highlight the potential of polysaccharide-terpene-functionalized biogenic AgNPs as a sustainable alternative to conventional fungicides, supporting their application in precision agriculture and integrated crop protection strategies.

Fungal pathogens pose serious threats to global agriculture, causing substantial crop loss and food security concerns. Current solutions often rely on conventional pesticides, generating negative environmental impacts. This study presents the development of two novel multifunctional hybrid nanoparticles designed to provide a sustainable alternative for crop protection and growth promotion. These nanoparticles are based on dendritic mesoporous silica nanoparticles (dMSNs) and functionalized with innovative coating agents derived from cinnamaldehyde- (CIN) and β-cyclocitral (βETA) -modified polydopamine (DOPA). The purpose of this research was to create a system that could deliver antifungal agents and support plant development simultaneously, especially under pathogen-induced stress. Nanoparticles exhibited a dual-release mechanism with pH-responsive kinetics, releasing up to 94 % of geraniol (GER) and 81 % of compound βETA, at pH 5. This confirms their ability for targeted, stimulus-triggered delivery. In vitro tests showed strong antifungal activity against several plant pathogenic fungi, with minimum inhibitory concentrations down to 0.078 mg/mL. Microscopic analysis revealed significant disruption of fungal mycelia after treatment, confirming the antifungal mechanism. In vivo biosafety was established through assays on Drosophila melanogaster. Furthermore, experiments on plants infected with Fusarium oxysporum demonstrated enhanced seed germination and early plant development. Treated plants showed improved root and shoot growth, higher chlorophyll content, and restored levels of key physiological markers like polyphenols and carotenoids. This study reports two dual-functional nanoparticles that improve the control of fungal pathogens while simultaneously promoting early plant development. The findings highlight their potential as sustainable nanobiotechnological tools for protecting crops and enhancing productivity in agricultural systems affected by fungal diseases.