Copper nanoflowers as effective antifungal agents for plant pathogenic fungi.

Flower-shaped copper nanoparticles were synthesised by a green and ecofriendly chemical reduction approach using copper sulphate and cytyltrimethal ammonium bromide. The UV-vis spectrophotometer analysis showed maximum absorption at about 552 nm, which is specifically reported for copper nanoparticles. The crystal lattice structure of copper nanoflowers was confirmed by X-ray diffraction analysis. Further, the transmission electron microscopic studies revealed the flower shape copper nanoparticles in the size range of 100-500 nm. The stability of thus synthesised copper nanoflowers was assessed by zeta potential analysis, which was found to be 35 mV indicating the most stable nature of nanoflowers. The antifungal activity of these copper nanoflowers was evaluated by Kirby-Bauer disk diffusion method against selected common plant pathogenic fungi. It was found that the chemosynthesised copper nanoflowers demonstrated significant inhibitory activity against the plant pathogenic Aspergillus niger, Fusarium moniliforme, F. culmorum, F. oxysporum and F. tricinctum. The maximum antifungal activity was shown against A. niger followed by F. moniliforme, F. oxysporum and F. tricinctum, whereas the minimum activity was reported against F. culmorum. Similarly, the effect of the copper nanoflowers was also evaluated in combination with commercial antifungal agent (ketoconazole), which demonstrated the enhanced activity of antifungal agent.