Quaternized Chitosan-Capped Mesoporous Silica Nanoparticles as Nanocarriers for Controlled Pesticide Release

Abstract

Nanotechnology-based pesticide formulations would ensure effective utilization of agricultural inputs. In the present work, mesoporous silica nanoparticles (MSNs) with particle diameters of ~110 nm and pore sizes of ~3.7 nm were synthesized via a liquid crystal templating mechanism. A water-soluble chitosan (CS) derivative (N-(2-hydroxyl)propyl-3-trimethyl ammonium CS chloride, HTCC) was successfully capped on the surface of pyraclostrobin-loaded MSNs. The physicochemical and structural analyses showed that the electrostatic interactions and hydrogen bonding were the major forces responsible for the formation of HTCC-capped MSNs. HTCC coating greatly improved the loading efficiency (LC) (to 40.3%) compared to using bare MSNs as a single encapsulant (26.7%). The microstructure of the nanoparticles was revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The pyraclostrobin-loaded nanoparticles showed an initial burst and subsequent sustained release behavior. HTCC-capped MSNs released faster than bare MSNs in the initial stage. Pyraclostrobin-loaded HTCC-capped MSNs with half doses of pyraclostrobin technical demonstrated almost the same fungicidal activity against Phomopsis asparagi (Sacc.), which obviously reduced the applied pesticide and enhanced the utilization efficiency. Therefore, HTCC-decorated MSNs demonstrated great potential as nanocarriers in agrochemical applications.

Ag decorated silica nanostructures for surface plasmon enhanced photocatalysis

“…7 Mesoporous silica, due to its large surface area, high hydrothermal stability, and diverse surface functionality, has been explored extensively for biomedical applications, namely cell imaging, diagnosis, biosensing, intracellular drug delivery [8][9][10][11][12][13][14][15] and controlled pesticide release. 16 The presence of silanol groups ensures better adsorption of dye molecules on its surface. 17 Researchers have investigated photocatalytic activity of various nanoparticles (NPs) including TiO 2 , 18 ZnO, 19,20 MnO 2 , 21 Silver, 22 etc.…”

Facile synthesis of microporous SiO2/triangular Ag composite nanostructures for photocatalysis

“…Microporous silica nanoparticles were synthesized using CTAB as a structure-directing agent and TEOS as precursor as reported by (Cao et al 2016) with a slight modification. The obtained particles were coded as MS-60, MS-75 and MS-90 according to reaction time, i.e., 60, 75 and 90 min, respectively.…”

“…Mesoporous silica due to its large surface area, high hydrothermal stability, and diverse surface functionality, has been explored extensively in biomedical applications, including cell imaging, diagnosis, biosensing, intracellular drug delivery (Argyo et al 2013;Bharti et al 2015;Chen 2016;Huang et al 2014;Sharma et al 2014;Sharmiladevi et al 2016;Tang and Cheng 2013;Zhang et al 2015) and controlled pesticide release (Cao et al 2016). The morphology and the particle size of mesoporous silica strongly influence the absorption and release of drug/pesticide (Lu et al 2009).…”

Naturally Occurring and Synthetic Mesoporous Nanosilica: Multimodal Applications in Frontier Areas of Science

“…Various studies were conducted to deliver chemicals such as pesticides into plants using MSNs as delivery agent. 133,[150][151][152] Recently, an intracellular glutathione (GSH) responsive abscisic acid (ABA) delivery system has been developed based on thiol gated MSNs. 153 Monodispersed MSNs with particle diameter of $ 20 nm and pore size of $ 2:87 nm were synthesized and modi¯ed using decanthiol as gatekeepers.…”