Multidimensional response of dopamine nano-system for on-demand fungicides delivery: Reduced toxicity and synergistic antibacterial effects.

• Pro@MPDA-BIZ@β-CD was prepared by encapsulating Pro within polybdopamine carrier modified by benzimidazole and cyclodextrin. • Nano-pesticide with pH and near-infrared dual response, used in different administration modes. • Pro@MPDA-BIZ@β-CD showed excellent antifungal effects against Sclerotinia sclerotiorum. • Pro@MPDA-BIZ@β-CD showed better biological safety and wettability. Considering the microenvironment of pathogens, the use of highly biocompatible antibacterial materials loaded with fungicides and the on-demand delivery of fungicides through controlled release can effectively improve the biocompatibility and antibacterial effect of existing fungicides. In this study, we used mesoporous poly-dopamine nanoparticles (MPDA NPs) as a carrier, prochloraz (Pro) as a loading agent, and benzimidazole (BIZ) and β-cyclodextrin (β-CD) complex as a blocking agent to prepare the on-demand delivery nano-pesticides Pro@MPDA-BIZ@β-CD (hereinafter abbreviated as PMBD), which can be administered at different stages. Sclerotinia sclerotiorum secretes oxalic acid factor to create an acidic microenvironment, and the nano-system quickly releases fungicide Pro into the mycelium. MPDA materials also responds to oxalic acid to jointly reduce the pathogenicity of Sclerotinia sclerotiorum , effectively inhibiting the growth of Sclerotinia sclerotiorum , and realizing the treatment of Sclerotinia sclerotiorum infection. On the other hand, when plants are not infected with Sclerotinia sclerotiorum , MPDA with a photothermal effect triggers the release of fungicides under the irradiation of near-infrared light, thus preventing Sclerotinia sclerotiorum infection. The in vitro release experiment showed that the cumulative release of Pro under low pH and near-infrared light irradiation was 2.68 times and 2.04 times higher than that under neutral and no light conditions, respectively. On the other hand, the rich functional groups on MPDA-BIZ@β-CD(hereinafter abbreviated as MBD) gave the system good wettability, and the contact angles of MBD on Chinese cabbage and tomato leaves were reduced by 14.85° and 41.54°, respectively, which enhanced its resistance to rainwater erosion and prevented the fungicides from being lost to the environment. In addition, bio-safety experiments have shown that PMBD has good biocompatibility to plant germination and soil microorganisms. [ABSTRACT FROM AUTHOR]