Zein/sodium abietate complex stabilized pickering emulsion as a delivery system for controlled release of hydrophobic photosensitive pesticide

Inefficient use of pesticides and the consequent environmental problems have led to the development of low-cost, environment-friendly and efficient pesticide delivery systems. Pickering emulsions (PK) stabilized by zein are considered to have many application prospects in the delivery of pesticides. Herein, the function of zein was improved by non-covalent binding with sodium abietate (RA-Na). Tea tree oil (TTO) was used as the solvent for hydrophobic photosensitive pesticide, avermectin (AVM), and also as a component of the oil phase of emulsion. The emulsion AVM@PK was oil in water (O/W) type that had certain foliar affinity. Under the same conditions of UV irradiation, the AVM residual rate of AVM@PK system was 2.4 times that of commercial emulsion (EC), showing superior UV resistance. AVM@PK released AVM at a faster rate under acidic/ basic conditions in vitro than under neutral conditions, with a certain pH response. In vitro bioactivity tests showed that AVM@PK had good antibacterial activity and insecticidal activity equivalent to EC. This system is expected to be used to prevent some plant pests while also preventing or treating some bacterial diseases. It is a simple, environmentfriendly, low-cost, effective, and practical strategy for pesticide delivery.