The utilization of nanopesticides is a young and very promising direction in agriculture. Their use can significantly improve many parameters of the used drugs. Nevertheless, there are many disputes and hypotheses about the impact of such pesticides on the environment. There are many examples of nanopesticides in the literature with an inorganic active substance. They are widely used in practice and are sufficiently described in the literature. In this chapter, emphasis will be placed on the use of nanopesticides with photosensitive organic active substances. Methods for their preparation, effect on the target pathogen, and degradation pathways will be described.
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Nanotechnologies are becoming extra widespread and repeatedly moving from theoretical to practical environments. In chemistry, there are many publications about using various nanoparticles as reagents and catalysts. There is also a tremendous amount of work on producing macromolecules (fullerenes, rotaxanes, nanotubes, etc.), which can be attributed to nanoparticles in size and exhibit some exciting and unique properties compared with ordinary substances. Nanotechnology is well-represented in the pharmaceutical industry. There are examples of not only obtaining but also using nanoparticles. For instance, nanoencapsulation of the drug active substance is quite widely developed, which makes it possible to improve its solubility and, accordingly, bioavailability, and thus makes it possible to reduce the concentration of the active substance and thereby reduce the overall chemical load on the body. In addition, this approach provides a prolonged action of the drug. For this purpose, natural and modified saccharides (cyclodextrins, dextrans, pectin, chitin, etc.) are frequently employed in the pharmaceutical industry. Although nano preparations have been utilized in pharmaceuticals and their effect has been studied for a long time (Madhusudhan et al., 2017; Macaev et al., 2013; Luo et al., 2014; Bhattarai et al., 2010), they are not so common in agriculture. It is worth noting that today copper hydroxide nano preparations are almost universally used in agriculture to combat fungal plant diseases (Kaur et al., 2014). Despite promising prospects for the benefit of organically supported nanoparticles for plant protection, they are not expansively used in practice. Moreover, there are quite a few patents on this subject (Asrar, 2003, 2010, 2016; Carr, 1993; Doane, 1990; Dellicoll, 1980).
In addition, although agriculture, in general, has never been especially green, and there are many examples of the overuse of plant protection products and fertilizers in pursuit of high yields, the possibility of using nano pesticides has caused a lot of environmental disputes. However, there is a lack of systematic data on the fate of such products in the environment, and the possibility of evaluation of the nano pesticides by the current pesticide regulatory framework is unclear. At the same time, there are a limited number of examples in the literature of studying the pathways of degradation and removal from the environment of nano pesticides with organic active ingredient (AI), as well as their accumulation in soil, plants, and further along the food chain. It should also be comprehended that, despite the recent popularity of organic farming, the need to feed an ever-increasing population of the planet will lead to the continuous use of pesticides in ever-increasing quantities. The purpose of this chapter is to explore the available information on nano pesticides containing some organic active substances. It will consider the influence of nanocarriers on the photodegradation of the active substances in nanoformulations.