Bio-based mesh-like pesticide carriers via copper ions chelation for prolonging pesticide retention and flush resistance on foliage.

In the past few years, the development of smart pesticide-controlled release systems has emerged as an important strategy in modern precision agriculture, particularly to increase retention efficiency and improve the utilization of pesticides. In order to achieve effective retention of pesticide spraying formulations on foliage surfaces, the present study aimed to develop a novel bio‐based mesh‐like pesticide carrier (named PDA/HDA‐Cu/MEP@CNC), using polydopamine (PDA) and hexadecylamine (HDA) -coated cellulose nanocrystal (CNC), wherein copper ion was used for chelation. Fenitrothion (MEP) was used as a model pesticide in the study. The use of PDA/HDA‐Cu/MEP@CNC exhibited sustained stimuli‐response release behavior under an alkaline environment, which was attributed to the coordination of copper ions on CNC. The deposition efficiency of the prepared PDA/HDA‐Cu/MEP@CNC was enhanced owing to the presence of the PDA layer. In addition to this, the use of PDA/HDA‐Cu/MEP@CNC resulted in more than 75% enhancement in the antifungal activity towards Rhizoctoni solani (R.s.), as compared to commercial MEP. Further, the results for biosafety assessment demonstrated that the prepared pesticide carrier exhibited remarkable biosafety properties. Altogether, enhanced retention property, controlled release behavior, and biosafety activity of this modified nanocellulose based controlled release system highlighted its potential to be explored as a commercial formulation for pesticide spraying. • A natural biocompatible mesh-like pesticide carrier for prolonging pesticide retention on foliage was synthesized. • The biohydrogel by the coordination of copper ions on CNC provides large contact area and high pesticide loading capacity. • The mixed PDA greatly enhanced the deposition efficiency of the pesticide- loaded mesh-like biohydrogel. [ABSTRACT FROM AUTHOR]