Acidity-activated degradable Mn-engineered silicon nanohybrids coordinated with iprodione for high-efficiency management of Sclerotinia sclerotiorum and nutrient enhancement to crops

Nanocarriers that respond to environmental stimuli are highly desirable in optimizing the bioavailability of pesticides while minimizing side effects. Manganese-engineered nanomaterials hold promising prospects in agriculture as versatile carriers for both intelligent controlled pesticide delivery and crop nutrient enhancement. Here, Mn-engineered hollow silicon nanospheres (Mn-HSNs) with a bubble-like structure were synthesized for encapsulating iprodione (IPR) to obtain IPR-loaded Mn-HSNs (IPR@Mn-HSNs). Due to its high surface area of 261.28 m2/g and surface-enriched active sites, Mn-HSNs demonstrated a commendable loading capacity of 56.4 % for IPR. Results indicated that the -Si-O-Mn- hybrid framework of IPR@Mn-HSNs not only facilitated acidity-triggered IPR release capability but also served as a plentiful source of Mn ion and orthosilicic acid (Si(OH)4) to promote crop growth. The release amount of IPR in an acidic environment generated by Sclerotinia sclerotiorum of oilseed rape was 3.14 times higher than that under neutral conditions. In vitro experiments demonstrated that the antibacterial activity of IPR@Mn-HSNs was about 1.2 times higher than that of commercial IPR suspension concentrate. Appreciably, IPR@Mn-HSNs could be effectively transported to different parts of rapeseed plants through foliar spray, thereby enhancing the effectiveness of pesticide utilization. More importantly, IPR@Mn-HSNs had no discernible impact on the survival of Harmonia axyridis and were relatively safe for HL-7702 and HK-2 cells. Therefore, this work offers valuable insights into the development of an efficient and environmentally friendly pesticide nanoformulation for sustainable and eco-friendly plant protection in agriculture.