Synthesis of a novel nanopesticide and its potential toxic effect on soil microbial activity

Abstract

A new nanopesticide, carboxymethyl-bcyclodextrin-Fe 3 O 4 magnetic nanoparticles-Diuron (CM-b-CD-MNPs-Diuron), was synthesized from an inclusion complex of CM-b-CD-MNPs as host and diuron as guest molecules. The transmission electron microscopy revealed it had an average diameter of 25 nm which is more or less the same as that of MNPs (average diameter *23 nm). The CM-b-CD grafting was confirmed by infrared spectroscopy, and the amount of CM-b-CD grafted on the surface of MNPs was determined to be 144.1 mg/g by thermogravimetry. The feasibility of using CM-b-CD-MNPs as a nanocarrier for loading diuron was verified by investigating the formation of inclusion complex. The complexation of CM-b-CD-MNPs with diuron followed the Langmuir adsorption isotherm. In this work, the potential toxic effect of CM-b-CD-MNPs-Diuron on soil microbial was evaluated by microcalorimetry, urease enzyme and real-time quantitative PCR (qPCR). The thermokinetic parameters were observed to decrease with increase in the loading of CM-b-CDMNPs-Diuron in soil. The urease activity data showed that there was a significant effect (p \ 0.05) of CM-b-CD-MNPs-Diuron on the enzyme activity. The microcalorimetric analysis was in agreement with qPCR, confirming the toxic effect of this nanopesticide on microorganism in soil.

Interaction between a nano-formulation of atrazine and rhizosphere bacterial communities: atrazine degradation and bacterial community alterations

“…42 For instance, similar increased toxicity to microbial enzyme activity was observed when applying carboxymethyl-β-cyclodextrin-Fe 3 O 4 magnetic nanoparticles-diuron as a nano-pesticide in soil. 43 We further demonstrated that the NPATZs might also potentiate the activity of ATZ against the non-target rhizosphere bacterial community. The enhanced biological activity of NPATZs could be attributed to the delivery efficiency of ATZ to the rhizosphere microbial communities e.g.…”

Effect of controlled release formulations of diuron and alachlor herbicides on the biochemical activity of agricultural soils

“…However, low urease activity was observed in soils spiked with diuron [52], but, on the contrary, Liu et al [53] observed inhibition of this enzymatic activity. Such difference may be explained by the different diuron rates used in these studies: 3 mg kg -1 in Fernandez-Bayo's study [52] and 5000 mg kg -1 in Liu`s [53].…”

Interactions of Nanoenabled Agrochemicals with Soil Microbiome

“…While the impact of metal and metal oxide nanoparticles on the soil microbiota as non-target organism have been addressed in the literature, those of nanoformulation of pesticides still stay poorly documented. Liu et al (2014) synthesized a new nanopesticide CM-ß-CD-MNPs-Diuron (average diameter of 25 nm by TEM) from an inclusion complex of cyclodextrin-Fe3O4 magnetic nanoparticles as host and diuron as guest molecules. Their potential toxic effects on soil microbiota was evaluated by microcalorimetry, measure of urease enzyme activity and qPCR.…”