Comparison between using of nanochitosan and nanostarch as the polymers in pesticide nanoformulations synthesis.

Chitosan, as a natural polysaccharide is considered the main polymer in nanopesticide formulation synthesis. As a result of the high price of chitosan, it's badly needed to find another polymer that is cheap and at the same time effective. So, starch as a natural polysaccharide was used as a polymer in nanopesticide formulations. In this work, some insecticides (acetamiprid, chlorfenapyr, emamectin benzoate, etofenprox, imidacloprid and indoxacarb) were loaded on both nanochitosan and nanostarch. By using zeta potential and particle size, the nanoparticles of all tested insecticides loaded on chitosan were 287.5, 99.9, 78.8, 696.6, 685.9 and 295.3 nm for acetamiprid, chlorfenapyr, emamectin benzoate, etofenprox, imidacloprid and indoxacarb, respectively. The corresponding results with starch were 176.1, 342.0, 647.8, 178.8, 809.1, and 68.7 nm, respectively. The zeta potential (charges) of all tested nanoformulations that loaded on chitosan were 0.9, 6.7, 4.2, 9.3, 11.1 and 4.8 mV for acetamiprid, chlorfenapyr, emamectin benzoate, etofenprox, imidacloprid and indoxacarb, respectively, while loading on starch was 4.7, 7.5, 12.9, 19.6, 28.5 and 8.6 mV, respectively. The loading capacity of all tested insecticides was 59.5, 50.6, 44.6, 55.6, 41.1 and 53.2%, respectively, for the chitosan nanocarrier; and 45.8, 46.3, 31.9, 33.7, 35.1 and 51.7%, respectively, for the starch nanocarrier. The obtained results indicated that starch was very effective as a polymer compared with chitosan. The charges of nanostarch were more than those of nanochitosan. This means that the nanostarch formulation was more homogenous than nanochitosan. These results found that starch is a very cheap material, stable, biodegradability, and ease of preparation compared with chitosan. So, starch is considered a promising polymer in nanoformulations as a carrier material, and it can be used in nanopesticide formulations.