Core/Shell Dual-Responsive Nanocarriers via Iron-Mineralized Electrostatic Self-Assembly for Precise Pesticide Delivery

It is desirable for a simple and universal method to synthesize stimuli-responsive nanocarriers to targeted delivery of pesticides. In this study, a novel pH-value and laccase dual-responsive nanopesticide system loaded with lambda-cyhalothrin (LC) is established by iron mineralization after electrostatic self-assembly between sodium lignosulphonate (SL) and dodecyl dimethyl benzyl ammonium chloride (DDBAC). These nanoparticles are core-shell structures in which iron mineralization plays a key role in stabilizing the nanoparticles. This synthesis strategy is suitable for encapsulating hydrophobic and low-volatility compounds. The encapsulation of the nanocarriers prolongs the half-life of the LC under UV irradiation by 4.4-fold. After irradiation, the mortality of Agrotis ipsilon treated by the LC@SL/DDBAC/Fe is approximately 39% higher than that treated by emulsifiable concentrate (EC) at the concentration of 1 mg L-1. The dual-responsive property of lignin-based nanoplatform to alkalinity and laccase enable cargo release on demand. Although the toxicity of EC and LC@SL/DDBAC/Fe to A. ipsilon is similar, that of LC@SL/DDBAC/Fe to Brachydanio rerio is decreased by 11.57-fold, and the toxicity selective pressure is enhanced by 11-fold compared with EC. The SL/DDBAC/Fe nanocarriers represent a simple preparation procedure, excellent environmental safety, and dual-responsive release profiles and can offer a promising nanoplatform for precise pesticide delivery.

Automated summary

A novel pH-value and laccase dual-responsive nanopesticide system loaded with LC was successfully established in this study, with nanoparticles stabilized through iron mineralization, prolonging the half-life of LC and increasing mortality of pests. This synthesis strategy shows potential for precise pesticide delivery with excellent environmental safety.