Fe₃O₄ Magnetic Cores Coated with Metal–Organic Framework Shells as Collectable Composite Nanoparticle Vehicles for Sustained Release of the Pesticide Imidacloprid

Abstract

nanocomposite was verified by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and zeta potential test. The magnetic collectability of Fe 3 O 4 @PDA@UiO-66 was demonstrated through a magnetic hysteresis loop study (∼2 emu/g) and magnetic collection experiment (up to a 96% collection rate). Imidacloprid (IMI) was employed as a model pesticide to be loaded into the Fe 3 O 4 @PDA@UiO-66 nanocomposite, with 15.87% drug loading. IMI was found to exhibit sustained-release behavior after being loaded into the delivery vehicle, and magnetic Fe 3 O 4 @PDA@UiO-66 can be readily collected after IMI release, which is beneficial to constrain the hazardous effects of the vehicles and the residual pesticide on the ecosystem. The insecticidal activity of IMI@Fe 3 O 4 @PDA@UiO-66 toward Aphis craccivora Koch was found to be superior to that of free IMI, and the efficacy was comparable to that of the commercial 70% IMI water dispersible granule, indicating its potential as a magnetic collectable green carrier for pesticides in agriculture.

Recent development in functional nanomaterials for sustainable and smart agricultural chemical technologies

“…Biodegradable synthetic polymers, specially polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA) are also attractive candidates for nano entrapment. They can Porous Silica Nanosphere /Imidacloprid [49] Zirconium-based MOF /Pyrethroids [59] Iron-Based MOFs /Chlorantraniliprole [60] Aluminum-Based MOFs/ Azoxystrobin and Diniconazole [61] Iron-based MOFs /Diniconazole [62] Fe 3 O 4 -MOF Core-shell Nanocarrier/Imidacloprid [63] Zinc MOF /ortho-Disulfides Entrapment With Further Modification with β-Cyclodextrin [64] be eventually degraded into environment-friendly lactic acid and glycolic acid monomers, while their hydrophobic nature also offers a good affinity to pesticide molecules [38,39]. Employing PLA as the entrapping matrix, Liu and co-workers [40] prepared porous microspheres via a PME process to achieve sustained release of pesticide chlorantraniliprole.…”

“…Similarly, Shan et al coated polydopamine on diniconazole loaded MOF carrier so that the fungicide could be released in different rate according to pH changes in the environment [62]. In another work, Fe 3 O 4 -MOF core-shell nanocarriers was synthesized to physically adsorb imidacloprid [63]. Since they are magnetic, the nanoparticles were expected to be retrieved magnetically after active loadings are released, minimizing environmental impacts of the carriers and the residual pesticide.…”

“…Taking nanopesticides for examples, release kinetics studies examined under lab-manipulated operational conditions can be very different from in-field conditions going through seasonal weather stresses in terms humidity, temperature, wind, and UV exposure. Nanopesticides with magnetic Fe 3 O 4 cores, which are considered retrievable to reduce the hazardous effects of the carriers and the residual pesticide [63], could lose the magnetic Fe 3 O 4 cores due to structural interruptions under corrosive oxidation and photo attacks. Similarly, the valve opening threshold of the stimulated-release nanopesticides may also lose their sensitivity under in-field conditions.…”

pH-Responsive ZIF-8-Based Metal–Organic-Framework Nanoparticles for Termite Control

“…An environmentally safe carrier can not only improve the efficiency of pesticide use but also greatly improve its safety, both for the environment and for the human body. 10,11 Nanoparticles based on metal−organic frameworks (MOFs) have become one of the most promising classes of drug delivery vehicles owing to their high capacity, tunable release, and the potential to simultaneously transport several different payloads to achieve synergistic therapeutic effects. 12,13 ZIF-8 is a zeolitic imidazolate framework built from Zn 2+ and 2methylimidazolate, a typical material in this series.…”

Synthesis of semicoke-based geopolymers as delivery vehicles for slow release of herbicides

“…Hence, it is necessary to endow the carrier with environmental stimuli-responsive characteristics and develop an intelligent controlled-release system. 33 The stimulus-response systems for pH value, 34 magnetic properties, 25,35 temperature, 36 and redox enzymes 37 were reported. 38,39 However, there are few reports of porous GPs as carriers for the slow release of pesticides.…”