NanoFASE Case Study: Fate of Cu(OH)2 nanowires utilised as pesticides

Nanoparticles are of interest for agrochemicals such as pesticides because they may promote more efficient, precise application of active ingredients, reduced loss of product outside the target area, and improved bio-interactions such as uptake by organisms. Nanopesticides take advantage of different types of nanocarriers (e.g., nanocapsules, nanowires, etc.).

NanoFASE set out to understand the fate of copper hydroxide Cu(OH)2 nanowires (NWs) utilised as pesticides once they are in contact with:

•    soil in which the particles might sorb
•    the associated soil pore water, in which the particles may undergo dissolution
•    soil-dwelling organisms (e.g. earthworms, isopods, etc.) and plants (e.g. wheat, etc.).

Dysprosium doped Cu(OH)2 was synthesised to facilitate investigation of the bio-accumulation potential of Cu-containing nanowires in living organisms, allowing discrimination between the engineered NWs and free Cu2+ cations, as well as the engineered NWs and in situ precipitated nanomaterials by element mapping on TEM or SEM, or discrimination of ions and ENMs by spICP-MS for ENM quantification and characterisation of composition (elemental ratio).  

 
 
Image credit: Food and Environment Reporting Network; Stacey Harper, Oregon State University

Relevant Processes

 
  • Attachment efficiency of Cu(OH)2 NWs to clay, humic substances etc.
  • Dissolution (amount and rate) of Cu(OH)2 NWs and influence of pH, DO, ionic strength, humic content etc. 
  • Speciation of the Cu following dissolution. Re-precipitation of particles, interaction with other ions (e.g. Cl-, S- etc.) and solubility constants (and predicted relative %) for the various species
  • Quantification of total bio-uptake (excluding gut load) and localisation of metal ions / NPs
  • Determination of uptake mechanism and uptake form (species) and distinction between uptake of ions / particles, and engineered / re-precipitated particles
     

Emitted to

 
  

 

   Agricultural soil                      Organisms (or plants) in agricultural soil

 

  

Read more

Read also
 
 
Kah, M., Kookana, R.S., Gogos, A., Bucheli, T.D. (2018) A critical evaluation of nanopesticides and nanofertilizers against their conventional analogues. Nature Nanotechnology 13, 677–684. https://www.nature.com/articles/s41565-018-0131-1  

Neves Joana, Cardoso Diogo N., Malheiro Catarina, Kah Melanie, Soares Amadeu M. V. M., Wrona Frederick J., Loureiro Susana (2019) Copper toxicity to Folsomia candida in different soils: a comparison between nano and conventional formulations. Environmental Chemistry, https://doi.org/10.1071/EN19061

Contact

 

Susana Loueiro

University of Aveiro

Email: sloureiro@ua.pt 

 

 

 

Iseult Lynch

University of Birmingham

Email: i.lynch@bham.ac.uk