Fabrication a controlled-release pesticide for improving UV-shielding properties and reducing toxicity via coating polydopamine

Abstract

Controlled-release formulations (CRFs) have potential applications in modern agriculture, for it can not only prolong the duration of agrochemicals but also alleviate the adverse effect on non-target organism. In this study, we constructed pyraclostrobin@SiO₂@polydopamine microcapsule (Pyr@SiO₂@PDA MC). The resulting microcapsule is a near-rod shape (about 1.15 μm), which has a drug-loading efficiency of 55%. Fourier transform infrared (FTIR) and thermogravimetric analysis (TG) revealed the successful entrapment of the pesticide. The coating of polydopamine (PDA) endowing the microcapsule with superior UV-shielding properties than pyraclostrobin@SiO₂ microcapsule (Pyr@SiO₂ MC). Compared with pyraclostrobin emulsifiable concentrate (EC), the Pyr@SiO₂@PDA MC exhibited 9.07-, 5.50-, 4.93- and 4.16-fold higher fungicidal activity against Rice blast fungus (Pyricularia oryzae) at concentrations of 0.5, 1, 2 and 4 mg/L. Moreover, acute toxicity tests demonstrated that the sample on zebrafish with lower toxicity on the first day. These results showed that the obtained microcapsule may process broader application potential in agriculture.

Keywords:

• Pyraclostrobin
• polydopamine
• sustained release
• bioactivity
• acute toxicity evaluation

Disclosure statement

The authors declare that they have no competing interests.

Additional information

Funding

This work received financial support from the National Key Research and Development Program of China: Special project on comprehensive technology development for chemical fertilizers and pesticides to reduce application and increase efficiency (2016YFD0201200).