Coumarin-Based Light-Responsive Composite Nanochannel Membranes for Precise Controlled Release of Pesticides

The precise, controllable, and safe application of pesticides can effectively reduce pesticide consumption and minimize chemical pollution at the source. Here, a light-responsive controlled-release system with flexible control, precise release, easy recovery, and suitability for future pesticide application in aquatic environments is proposed. The system precisely controls the release of pesticides through a light-responsive composite nanochannel membrane (CTC@SNM/PET) with reactive coumarin derivatives (CTC) as gating molecules. The prepared nanochannel membrane has an ultrathin thickness of 67.5 nm and well-ordered vertical nanochannels with a uniform size of 1.9 nm, providing a prerequisite for precise molecular gating and high permeability for mass transport. CTC monomers can realize cycloaddition/cyclocracking and nanochannel closing/opening to control the release of pesticides by controlling 365/254 nm ultraviolet light irradiation. As a proof of concept, the light-responsive controlled-release system based on CTC@MSF/PET against Saprolegnia parasitica achieves an inhibition rate of more than 95% and reduces pesticide residues by 56.5% compared to the control group. The proposed membrane system has great application potential to easily enable remote, quantitative, timed, and positioned pesticide application, thereby reducing pesticide residues and providing a prospective approach to reducing environmental and human risks. The developed coumarin-based light-responsive composite nanochannel membrane is the core of the controlled-release system, which can reversibly switch and regulate its mass transfer state under irradiation with 365/254 nm UV light. The constructed controlled-release system features flexibility, adjustability, stability, and remote controllability and is expected to be applied for the controlled release of functional substances in industries such as water treatment. image