Synthesis of copper/silica nanocomposites for application in preventing Ralstonia solanacearum bacteria causing the wilt disease

Abstract

This paper presented the synthesis at room temperature of copper/silica (Cu/SiO2) nanocomposites by the chemical reduction method with sodium borohydride as a reducing agent and polyvinylpyrrolidone as a stabilizer. The physicochemical properties of Cu/SiO2 were studied through ultraviolet–visible absorption spectrum, X-ray diffraction pattern, Fourier transform infrared spectrum, transmission electron microscope and energy-dispersive X-ray spectrum. Analytical results indicated that Cu/SiO2 contained copper nanoparticles with an average size of 6.78 nm, evenly distributed in the silica structure through chemical bonds. The antibacterial activity of Cu/SiO2 was evaluated by testing its activity against Ralstonia solanacearum bacteria that caused the wilt disease in plants. Cu/SiO2 could completely inhibit the growth of R. solanacearum bacteria at a concentration of 36 ppm, two times more effective than copper nanoparticles. The results showed that Cu/SiO2 nanocomposites would be potential for practical applications to replace traditional chemical pesticides in agriculture.