The preparation of bimetallic silver copper–silica nanocompositesfor antifungal application against fungi causing root rot disease

This paper presented the preparation of AgCu-SiO2 nanocomposite by green chemical reduction method combined with ultrasound. The physicochemical properties of AgCu-SiO2 were analyzed using techniques such as ultraviolet-visible absorption spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma mass spectrometry and atomic absorption spectroscopy. The analytical results indicated that the AgCu-SiO2 nanocomposite contained bimetallic nanoparticles of silver and copper, with sizes of 7.52 ± 1.12 nm. These nanoparticles were densely distributed on the silica surface. The antifungal activity of AgCu-SiO2 was compared to monometallic nanocomposites (Ag-SiO2, Cu-SiO2) and a commercial fungicide Ridomil gold 68 WG against Rhizoctonia solani, Fusarium oxysporum and Pythium catenulatum, causing collar rots disease on Solanaceae. The results showed that AgCu-SiO2 exhibited good fungal growth inhibition compared to the monometallic nanocomposites. Specifically, the AgCu-SiO2 nanocomposite with complete fungal inhibition at a concentration of 125 ppm against all three studied fungal strains suggested its potential as an effective alternative to conventional chemical active ingredients in managing root rot disease.