Graphene oxide-Fe3O4 nanocomposites as high-performance antifungal agents against Plasmopara viticola

Abstract

Plasmopara viticola, a causal agent of grapevine downy mildew, is a widely distributed pathogen, which can cause destructive disease in field-grown grapevines. Although fungicides are used to treat the disease, fungicide-resistant strains have been emerging. In this study, we developed graphene oxide (GO)-Fe3O4 nanocomposites, which could effectively repress the germination of sporangia and inhibit the development of downy mildew. 50 μg mL −1 GO-Fe3O4 showed excellent protective and fungicidal activities. 250 μg mL −1 GO-Fe3O4 on grapevine leaves in the field could significantly decrease the severity of downy mildew, suggesting its potent curative effect. Moreover, GO-Fe3O4 had no significant toxic effects on grapevine plants even at the concentration twice that of the highest dosage (1000 μg mL −1) used in this study. Our work suggested that GO-Fe3O4 would offer an important opportunity to develop new approach for controlling plant diseases.

Facile synthesis of polydopamine/reduced graphene oxide nanosheets with incorporated copper ions for high antibacterial performance

“…2.1. Synthesis of Cu/PDA/RGO nanosheets: GO was prepared according to the procedure described by Wang's team [27]. Then the Cu/PDA/RGO nanosheets were typically synthesised as follows: 200 mg GO was dispersed in 200 ml DI water, and the resulting suspension was sonicated in an ice-bath for 1.5 h.…”

“…GO was prepared according to the procedure described by Wang's team [27]. Then the Cu/PDA/RGO nanosheets were typically synthesised as follows: 200 mg GO was dispersed in 200 ml DI water, and the resulting suspension was sonicated in an ice‐bath for 1.5 h. Then 200 mg dopamine hydrochloride and 200 ml Tris‐buffer solution (10 mM, pH 8.5) were added to the above suspension and subsequently stirred for 12 h at room temperature to obtain the composites of reduced GO (PDA/RGO).…”

Polydopamine‐functionalised graphene–Fe 3 O 4 –Ag magnetic composites with high catalytic activity and antibacterial capability

“…The Fe 3 O 4 NPs and graphene oxide (GO) were prepared using the method previously described by our group [8, 9]. To prepare PGFA composites, dopamine hydrochloride (10 mg) and Fe 3 O 4 NPs (12 mg) were added to 10 ml of GO aqueous dispersion (2.5 mg/ml).…”

Nanohybrid Antifungals for Control of Plant Diseases: Current Status and Future Perspectives

“…Downy mildew is a disease caused by Plasmopara viticola in grapes plants that leads to extremely heavy yield loss. To combat the disease, a nanocomposite construct consisting of Graphene oxide (GO) and Iron oxide (Fe 3 O 4 ) as GO-Fe 3 O 4 nanocomposite was developed [ 39 ]. The study demonstrated that the pretreatment of the leaf discs with nanocomposite followed by inoculation with P. viticola sporangium suspension strongly inhibited the spore germination.…”

“…This effect may be attributed to the blockage of the water channels of sporangia by surface adsorption of the nanocomposites. From the images, it is evident that bare GO and Fe 3 O 4 possessed moderate spore germination inhibition activity while the nanocomposites triggered stupendous activity [ 39 ].…”