A super long-acting and anti-photolysis pesticide release platform through self-assembled natural polymer-based polyelectrolyte

Developing long-acting and sustained release systems is a feasible and effective way to increase the efficiency of pesticides and help improve environmental pollution issues, especially for photosensitive pesticides. Here, an environment-friendly emamectin benzoate-loaded alginate/chitosan/sodium lignosulfonate (EB-loaded ALG/CS/SL) polyelectrolyte was successfully prepared via layer-by-layer self-assembly. The results of fourier transform infrared spectroscopy, thermogravimetric analyses, powder X-ray diffraction, size distribution and zeta potential analyses confirmed the formation of EB-loaded ALG/CS/SL via electrostatic interactions without chemical reaction, which would not affect the performance of emamectin benzoate (EB). Besides the high encapsulation efficiency (93.3 ± 2.08%), this protective coating strategy exerted an outstanding performance of sustained-release (up to 204 h) and anti-photolysis for EB. As a result, the degradation amount of EB in EB-loaded ALG/CS/SL could be reduced for 5.7 times than that of uncoated EB under UV light. This study provides a new natural polymer coating strategy to reduce loss of pesticides to non-target environments, and will extend the applications of rich natural polymer resources.