Intelligent response release of imidacloprid from a tailored star-shaped polymer targeting the temperature-dependent reproduction of cotton aphids

Intelligent response carriers have been developed and widely used in agriculture to improve pesticide utilization. However, there are few tailored response carriers that are targeting the cotton aphid pest. Based on the temperature-dependent growth and reproduction of cotton aphids, we constructed a tailored temperature-responsive star-shaped polymer to achieve on-demand controlled release of imidacloprid (IMI) to more effectively kill cotton aphids. In this work, a series of star-shaped polymers based on β -cyclodextrin ( β -CD), 2-(2-methoxyethoxy)ethyl methacrylate (MEO 2 MA), and tert -butyl acrylate ( t BA) were synthesized via atom transfer radical polymerization (ATRP). Next, β -CD-PMEO 2 MA ( β -CD-P0) micelles were developed having different controlled release rates of IMI at different temperatures (14, 21, or 27°C) following the cotton aphid growth and reproduction cycle. At 21°C, the micelle underwent a phase transition from a solution state to a turbidity state. By inducing this structural change, release of IMI was increased to adapt to the reproduction of the cotton aphid population which is highest at 21–27°C. In vitro release experiments showed that 48% of IMI was released from β -CD-P0 after the phase transition temperature (PTT). An aqueous solution of the β -CD-P0 polymer micelle was stable at 4°C for at least 28 days. Therefore, this intelligent response release model has enormous potential as a novel carrier for various pesticides.