Evaluation of ALA-capped silver, copper, and silver-copper nanoparticles for controlling fungal plant pathogens

Phytopathogenic fungi significantly threaten global food security, causing substantial yield and quality losses. Sustainable solutions are urgently needed to combat these agricultural pathogens. This study explored the potential of silver (Ag), copper (Cu), and combined Ag/Cu nanoparticles capped with aminolevulinic acid (ALA) as antifungal agents. The nanoparticles (ALAAg, ALACu, and ALAAgCu) were synthesized via photoreduction and characterized using various techniques (UV-Vis, TEM, XRD, Zeta potential). Their antifungal activity against four key plant pathogens (Alternaria grandis, Colletotrichum truncatum, Corynespora cassiicola, and Fusarium oxysporum) was evaluated using poisoned food techniques. Notably, ALAAgCuNPs demonstrated superior antifungal activity compared to a conventional fungicide against two fungal strains. Even at lower concentrations, ALAAgCuNPs exhibited fungistatic effects comparable to those of the control. These promising results suggest the potential of ALAAgCu NPs as a broad-spectrum, potentially eco-friendly alternative for fungal control in plants and seeds. This approach is crucial for ensuring crop health, harvest quality, and food safety.