Accelerated discovery of metastable but persistent contact insecticide crystal polymorphs for enhanced activity and sustainability
The World Health Organization estimates that malaria and other vector-borne infectious diseases, such as Zika or dengue fever, are responsible for more than 700,000 deaths worldwide annually. An essential component in the fight against malaria is the control of disease vectors through the use of contact insecticides for indoor residual spraying and insecticide-treated nets. Contact insecticides are powders of organic crystalline materials. As mosquitoes rest on the powder particles, they absorb the active substance through their tarsi (feet) to lethal effect. New York University investigators previously demonstrated that the efficacy of contact insecticides strongly depends on the identity of their crystalline forms, otherwise known as polymorphs, which have identical molecular compositions but different crystal structures. The more active polymorphs must also exhibit a high stability against transformation to less active polymorphs for the duration of their application. The central objective of this project is a knowledge-guided design, through computation and experiment, of metastable crystalline forms with superior properties for their target application. In the context of contact insecticides, this will allow less toxicant to be used, reduce environmental impact, and, thereby, meet key sustainability goals on multiple fronts. Various workshops, including Computer Crystals for Kids, Machine Learning for Kids, and Crystal Kaleidoscope, will convey the science of the project to K-12 students. Special attention will be provided to engage Black, Latino, and Native American students through the Collegiate Science Technology Entry Program.