Pillar[6]arene@quantum-Dot Membrane for Controlled Release Pesticides Based on Host–Guest Chemistry

Controlled release of pesticides is highly desirable for improving efficacy and reducing side effects in agricultural applications. Herein, in this work, based on the optical property and host–guest chemistry of quantum dot and pillararene, we develop a new type of fluorescent, current-responsive, pH stimuli-responsive pillar[6]arene@quantum dots mixed-matrix membranes (PQDs-MMMs) for pesticide delivery, which achieves highly selective detection and controlled release for methyl viologen (MV2+). In the experiments of fluorescence spectrum and I–V current, PQDs-MMMs could realize the visual fluorescence detection and current selection for MV2+. Moreover, the controlled release experiments indicated that the PQDs-MMMs could effectively immobilize and stimuli-release the MV2+ depending on the pH regulation, which achieved the pH-stimuli-responsive release of MV2+. Additionally, the herbicidal activity of MV2+-loaded PQDs-MMMs (MV2+@PQDs-MMMs) was tested, and results showed the weed control effects were identified to free MV2+ under pH control. This work provides the great potential of PQDs-MMMs used in agricultural membranes with environmentally friendly and stimuli-responsive release.