An Alkali-Triggered Polydopamine Modified Mesoporous Silica Nanopesticide for Smart Delivery of Chlorpyrifos with Low Loss

Abstract

The development of nanotechnology provides a feasible and effective way to reduce pesticide loss and improve pesticide utilization. In this study, we created chlorpyrifos-loaded mesoporous silica nanocomposites modified with polydopamine (Cpf-MSNs@PDA) for the smart control of pests. The release of Cpf from the nanocomposite was alkali triggered and temperature dependent, guaranteeing the sustained and steady effectiveness of the active constituent with prolonged persistence time. The modification with PDA endowed the nanocomposite with better foliar adhesion and rain erosion resistance. Compared with Cpf, the leaf slip angle of Cpf-MSNs@PDA was increased from 27° to 60°, and the rain erosion loss was reduced by 2.6 times. The insecticidal persistence of the Cpf-MSNs@PDA nanopesticide was measured and found to be better than that of commercial Cpf with bi-insecticidal pathways. In pathway 1, a small portion of Cpf (16.7%) was released from Cpf-MSNs@PDA in vitro to perform contact toxicity on Mythimna separata, which shows an advantage of sustained release. In pathway 2, after being ingested, the alkaline midgut microenvironment of M. separata triggered the degradation of Cpf-MSNs@PDA, inducing the release of all the Cpf to exert acute gastric toxicity. These results highlight the potential of a nanopesticide in the delivery of an active pesticide ingredient with low loss and high efficiency. The design of a smart nanocomposite for the control of a specific type of pest or disease provides ideas for the development of sustainable agriculture.

One‐pot method for instant nanoformulation via self‐assembling of alginate with quaternary ammonium for controlled release of emamectin benzoate

“…Mythimna separata belonged to the order Lepidoptera , of which the environment in the midgut was generally basic 33 . As illustrated in Figures 5–7, incorporating into the nanoparticle reduced the release of EB, especially in basic environment.…”

“…Mythimna separata belonged to the order Lepidoptera, of which the environment in the midgut was generally basic. 33 As illustrated in Figures 5-7, incorporating into the nanoparticle reduced the release of EB, especially in basic environment. The increase of the insecticidal activity of the nanoformulation was thus attributed to the enhancement in the penetrating ability of nanoparticles through the cell membrane of the insect.…”

A core–shell‐structured zeolitic imidazolate framework@cationic antimicrobial agent templated silica nanocomposite for tackling antibiotic resistant bacteria infection

“…The PBS with a pH = 5.5 was adjusted using an HCl solution. [ 40 ] Then the samples were incubated in a constantly shanking incubator at 25°C at 100 rpm. At specified time intervals, 0.5 mL of the sample was taken out for centrifugation at 13,000 rpm for 5 min and then the supernatant was analyzed by LC‐MS to determine the concentrations of BAC and 2‐MIM in the solution.…”

Porous Silica Nanocarriers: Advances in Structural Orientation and Modification to Develop Sustainable Pesticide Delivery Systems

“…To study the antiwashing properties of MSN-delivered pesticides, Kan and co-workers 97 conducted a simulation study to investigate the rain erosion loss of chlorpyriphos (Cpf) and polydopamine-coated MSN loaded with chlorpyriphos (MSN-PDA@Cpf) from rice leaf. They utilized an acid buret as a rainwater generator.…”

“…Several studies reported faster release of pesticide from surface-functionalized PSNs influenced by alkaline pH. ,,,, Gao and co-workers coated the surface of abamectin-loaded HSN with poly­(glycidyl methacrylate- co -acrylic acid) (P­(GMA-AA)) to investigate its pH-dependent release. The cumulative release of abamectin from HSN-(P­(GMA-AA))@Aba at pH values of 5 and 7 were 14% and 13%, respectively, after 15 days, whereas 87% of Aba released at pH 10 on the same day, indicating a base-triggered release of pesticide (Figure b).…”