Utilizing nanotechnology for pesticide delivery can enhance their uptake and distribution in plants, thereby boosting pesticide efficiency. Fluazinam, a highly effective broad-spectrum fungicide with unique mode of action, is hindered by its poor systemic conductivity, limiting its field control efficacy. In this study, fluazinam-loaded nanocapsules were developed, which exhibited significantly higher inhibitory activity against various Phytophthora species compared to the commercial suspension concentrate. Notably, the nanocapsules demonstrated pronounced effects on reducing ATP content in Phytophthora capsici and effectively controlled pepper blight and cucumber downy mildew. Tracking the distribution of fluorescein isothiocyanate (FITC) fluorescein-labeled fluazinam nanocapsules revealed their presence in roots seven days after treatment. High-performance liquid chromatography (HPLC) analysis confirmed the easy absorption and transport of fluazinam nanocapsules by pepper plants. Moreover, treatment with fluazinam nanocapsules significantly increased the expression of two exocytosis genes, FACP and RABF2a , in pepper tissues. Lastly, fluazinam nanocapsules were found to enhance the relative abundance of beneficial bacteria in the soil microbial community. This study presents a promising approach to enhance the upward transport capability of non-systemic pesticides, offering novel insights into their application and improved efficacy.
Shiying Zou,Changjun Hou,Huanbao Fa,Liang Zhang,Yi Ma,Liang Dong,Dan Li,Danqun Huo,Mei Yang
Carbon dots doped with nitrogen and sulfur (NSCDs) was prepared from l -cysteine with a hydrothermal method and applied to develop a fluorescent sensor to determine fluazinam . Characterizations of the NSCDs suggest that it provides abundant affinitive sites for recognizing fluazinam through molecular interactions including electrostatic, π-π stacking and hydrogen bonding interactions. Strong inner filter effect (IFE) leads fluazinam to quench the fluorescence of the NSCDs with high efficiency. Under optimized conditions, the fluorescent probe shows very good sensitivity and selectivity in a linear range from 0.05 μM to 4 μM, and the detection limit is calculated down to 10 nM. The proposed fluazinam sensor is demonstrated to be feasible for application in detecting this fungicide in soil and apple samples with satisfactory accuracy. Besides, NSCDs could also be used to fabricate visual paper-based testing stripes under a portable UV lamp with a detection limit as lower as 50 μM. The fluorescent material presented here provides a functional platform for simple yet facile in-field detection of fluazinam in related samples.
The polyethyleneimine-capped copper nanoclusters (PEI-Cu NCs) were prepared by using polyethyleneimine as protective agent and hydrazine hydrate as reducing agent. The PEI-Cu NCs possessed strong fluorescence intensity, excellent water solubility, good stability and high dispersion. The sample’s fluorescence could be selectively quenched by the addition of fluazinam. There was a good linear relationship between the relative fluorescence intensity of PEI-Cu NCs and concentrations of fluazinam in the range of 0.5–70 μM. The quenching mechanism might be dynamic quenching and inner filter effect (IFE). Significantly, the PEI-Cu NCs could be used to detect fluazinam as fluorescent probe in environmental water samples.
危险品化学品经营许可证（带存储）